That's pretty cool, I didn't know long-stem Scraeder tubes were available. If it weren't for a concern of weakening narrow rims I'd drill all my rims out to Schraeder. Fitting in a narrow rim is the only advantage Presta offers.

Perhaps.

With the old sewups, it was recommended to deflate the tires when not in use. So, the presta valves were handy. But, at least for me, those days are long past.

I still find them to be convenient.

Other advantage: because the only thing closing the check valve is the pressure differential the air itself is all it takes to open it so very hand pump friendly.

I'm liking Schwalbe's A\V (schrader) tubes threaded stem and ring nut against the rim, to push the pump head against

Number 4 & 5 both fit 349 Brompton wheels ... I keep a valve core tool as 1 valve cap.

Zero issues using adapters. I use them all the time since my pump gets alot of use at my clinic and gets worn to where it has trouble seating on Prestas. It's quicker for me to just spin on the adapter then to futz with the pump head. The adapters work perfectly.

I use 'em and inflate all my tubeless setups with them. Not sure if it's been mentioned, but if your stem is not long enough to bottom out the adapter that could be another source for the problem.

Have not read all the posts so don't know if it's been mentioned, but schrader chucks have valves in them. There's a broad post that must be pushed inward when the chuck is pressed onto the valve. This opens the valve in the chuck. The post is usually broad enough so that the perimeter of the valve presses it inward when the chuck is pressed onto the valve. If that doesn't happen reliably, air won't flow reliably.

the amount of material that is removed when drilling is insignificant. any fear of weakening I think is unfounded. also schraeder valves hold 120 lbs of pressure with absolutely no trouble at all. the trick is drilling straight through 2 walls and filing the burs, then coating the hole with some paint. it takes a little time but when you're done, you're done. it's not for everyone. if you don't mind carrying your own pump or CO2 device then you have no need for gas station pumps. also good bike shops like Landry's in Natick, MA carry the long stem schraeder tubes. they don't blink twice when I mention I drilled them out

got a picture of the inside of your pump chuck? is is like a cheap gas station pump? the gas station pumps near us are horrible, they have fat stiff center pins that require significant pressure to open

Sometimes a Schrader will clog up if you leave the valve off, where a Presta valve won't. Small thing I know, but it is a point for Presta. And easier to pump to high pressures or so they say.

I did get a grain of sand in my car valve once while off roading oversand and the valve leaked a little at the air station, but I could hear it and it was easy to clear by pressing the pin a couple times. but yeah caps were invented for a reason

It's a bike pump,not a compressor. The head works on both Presta and Schrader,but because it sees so much use it gets loosened up and I've found it's quicker to just use the adapter.