That was a 'competition' photo, yes? A large saddle bag has aero disadvantages - think it thru - if all you're carrying is a key/or keys - is there a better way to carry?
How do you carry the key/keys in 'swim', run?
Your personal situation is something which can only be addressed by you. BUT, the fastest way to increase your learning curve/performance curve is to learn from others who have and are climbing the same mountain, hiking the same long trail, wanting the same faster... That knowledge may be the most valuable thing you can get. It may require some changes on your end. What that can be is only what you decide.
My comments are purely to encourage thought, in some obvious directions which can give sizable gain. Not every direction.
You're getting some valuable insights here, but other experienced Triathletes,living in your area, your desert, can put that into better perspective and with better priorities...
Sure, Companies would love you to buy their 'best' products (price wise). But there is some very fine stuff available for well below even the current mid-price point...
https://www.backcountry.com/pearl-iz...v6-shoe-womens
We're not gonna do the work for you, nor can we. You need to determine WHAT you need to do, and find a way to get there. If you decide to 'shop', there's plenty out there.
It may require some work, digging and not getting $250-$400 shoes, or whatever else you decide you need. But there's good stuff out there...
https://www.rei.com/rei-garage/product/214672/garneau-jade-ii-cycling-shoes-womens?CAWELAID=120217890013764163&CAGPSPN=pla&CAAGID=118742105195&CATCI=aud-1396942685475
la-297455113653&cm_mmc=PLA_Google%7C21700000001700551_2146720007%7C92700061060353182%7CNB%7C71700000080 080004&gclid=CjwKCAjwrNmWBhA4EiwAHbjEQAJC0t9SPE2oyyzYYiN3nCcJLwmkYgWSnXKVk_H30jctKbYS5fmphhoCMaYQAvD _BwE&gclsrc=aw.ds
https://www.trisports.com/product/lo...xoCrtEQAvD_BwE
The "beginner's category' of shoes in the article shows some very fine shoes - way better than what you're using...
If you say you have 'power', getting it down to the wheels and the road is primary to any other improvements. Everything else you do to improve will depend on how good your connection is to the bike.
Don't know your Euro or Mondo size? Figure it out.
There is no 'hidden' something which will get you from 18 to 19 and to 20 without the work.
... here's one thing I would put vegas money on...
if you were to buy a 'real' Tri TT bike, without working on the other things, it won;t get you to 20, prolly won;t get you to 19... it will make the path smoother, maybe a little easier, but it's not 'magic'
Ride On
Yuri