There are ways to have your phone nearby and not be randomly bothered by it.

A magnet will not interfere with the display itself, nor the any of the phone electronics except if it has a compass/magnetic field sensor.

In your case the LG G3 probably has the magnetic sleep feature, a tiny sensor that puts the phone to sleep when the case is closed and the magnet was close enough to confuse it.

Maybe ironically, I have clipped the magnetic clasp off on my wife's phone case and replaced it with velcro. She was worried about it, or has the sensor or something - easier to just change it than troubleshoot a problem if any.

I know that the LG G3 phones touted some special cases with a circular window. Your explanation sounds very likely correct.

In my pocket.

Samsung Galaxy, water resistant. Always placed in my right-side jersey pocket, screen facing my body, typically with a single ear bud attached to it. No baggie ever, even in rain, sleet, and snow. Never an issue bouncing out on mtb, though you can feel it getting weightless on small jumps (which is all I'm capable of).

Bar mounted cradle. Use it as my dashboard / radio. I carry a ziploc in case it rains..

I use a cell phone arm band that most use for listening to music while they run. However, i simply wrap around my stem and it hangs down the head tube. You cant see the phone face so its pretty useless for anything except holding your phone.

I use the seat wedge for Fritz, and the Jandd frame wedge for Feathers. I prefer the Jandd because it makes my phone more accessible than the seat wedge while also getting it off my sweaty body.
I've been assured that my phone is "water proof" but I'll bet my stuff would prove to be the exception to the rule... I have trust issues...

I bought something that mounts the phone on my handlebars, but didn't like it. When I feel like tracking my ride, I just start the app and toss the phone in my bag. I find that I enjoy my ride more if I don't have the phone right in front of my face.

Commuting, in the pannier. I toured with a bar bag before the flip phone died, and like it so much I ride with one when I don't carry panniers now. It's Ortlieb, waterproof, like the panniers, so the monster phone goes in the bar bag if there's no panniers on the bike.

I'm also still using a flip-burner. I leave it in my kittier. Every week or so I pull it out and turn it on.

As for same number/two phones, probably not possible. If both phones are smartphones, then you could get a free Google Voice number and use it on both phones using the Google Voice app. 'Free' if on wifi, or using data if out&about. But if one phone is flip, apps are not available.

Jersey pocket, my last three phones have been waterproof so sweat or rain isn't an issue

I have a rear top rack back and I keep my phone in there. I have a ziploc bag in it in case it rains etc. If you're looking for the racer aesthetic I suppose that wouldn't work. For mountain biking I got a hard sided case that goes in my rear underseat bag.

I have no idea why anyone would say with a straight face that going riding without a cell phone is a good idea. A cell phone is a magic device that lets you communicate wireless with anyone you want including uber/lyft/taxis or emergency services. Why would you ride without it? Just be an adult (or actually perhaps a teenagers as they never answer their phones lol) and don't use answer your phone if it rings. Not hard. I see no reason to deal with the possible hassle of getting stranded or the rare emergency life threatening situation and not be able to get ahold of someone because you didn't bring your phone with you.

Cell phones have also made group rides a lot more mentally enjoyable for me as I know if I get dropped, I can always get back to my car via google maps or uber. One time I biked to the gym, locked up my bike, when I came out I tried to unlock my bike - something has failed inside the lock and it wouldn't unlock. As I had my cell phone with me I didn't have to go through a long tedious walk back to my car, or deal with the hassle of calling a friend and bothering them to pick me up, I just got Uber and for $10 got a ride back to my car. When I came back to pick up my friends bike my lock had started working again and I was able to unlock it so altogether it was basically no big deal.

I keep mine in a top tube saddle bad....only I put it behind the seat post on the arms of the rear rack.

Something like this...
https://www.amazon.com/dp/B01EWZ3HC6...ing=UTF8&psc=1

There are a million shapes and sizes and colors. On my old bike I kept it right behind the stem on the top tube but it just didn't fit well on my current bike that way so I found the alternate spot behind the seat.

Most have a case for the phone that sits on top but I never liked those.

I have a foam liner I custom cut to fit into one side of the bag so my phone is well protected while I ride. The other side is open and I keep my wallet and keys and stuff in there.

I leave the bag on the bike at all times. So there is always a phone storage option and a place for my keys. Never have to think about if I have pockets or if anything will fall out. Nor do I have to rely on a full pannier or trunk bag, which I never use when just riding for fun on the weekend.

And I keep a shower cap tucked under my saddle so if it rains I quickly put it out and coverage both sides of the mini saddlebag and then my phone is dry and so is my car's keyfob. (3rd image)

(The phone on the handlebars in the second picture is a dedicated phone for mileage and mapping. I hate the idea of my daily use phone being on the handlebars.)

^@Skipjacks, I love your setup! Definitely giving me ideas for mine haha.

OP, considering I normally ride in jeans, front pocket. If for some reason that's starts to bother me, into the ditty saddle bag it goes! I've gone down a couple times, not a scratch; minimal case.

I just let my phone get sweaty in my hip pocket and wipe it off afterward, but I think it's supposed to be splashproof.

My phone slips into a can cozy (the flat type that has the folded bottom) and then into a jersey pocket. This protects against sweat and provides minimal cushioning that I hope I'll never need. I can get to it easier (one handed) than if it's in a bag (two hands). The zip lock is in my saddle bag if needed.

Stopped reading at blasphemy.

Commuting/ road riding: I carry my phone in my pocket on my jersey in a Ziploc bag. It is in a case and has a tech armor screen protector. it works well. I like to be able to access it. I used to put in my Ortlieb panniers but have had a few experiences that make me put it in m jersey pocket.1. I once was stopped by a woman on the street about to have a seizure 2. I like to take pictures or 3. write down notes of idiot drivers

Mountain Biking: I put in Ziploc in my camelback backpack.

I use the Rokform Bike Mount. It replaces the stem cap.

https://www.amazon.com/gp/product/B0...2&tag=tcbse-20

It's very solid and can be adjusted for angle of view.

I'll let you know if I ever get one.

Very clever! ...and smart-looking! (unlike most of my modifications and customizations)

I've been wanting a second phone with the same number for a while. That way I could leave the more expensive phone at home and use the burner phone for calling if needed - and not worrying about it getting damaged while I'm riding.

You can swap the SIM card into a second phone easy enough (on most devices)

It takes a minute because you have to power down to switch the SIM card then power back up the new phone. But it'll work.

"Can cozy" that's a pretty good idea. I'll give that a shot.

I keep my screen facing away when it's in my pocket or jersey. I've dialed 911 a couple of times by accident through my clothing...