No need to be sorry, and sincere respect to your 1800 hours, sir. I shall not achieve that mark in my remaining lifetime. At some point (hopefully not soon) a well cared for BX23s will come on the market with under 1000 hours.
There are electronic levels that have Bluetooth. As far as cheap goes, yes, if you can mass produce a basic sensor, $50 is an achievable number, and the price points prove that. If you want to attach your phone in a convenient place then that solution already exists. Phone mounts are pretty cheap.
I used to do that sort of thing. I worked for HP, Fitbit, and Oura, among others (CS trained, EE by necessity, ME by hobby).
Moving the sensor to each attachment would be pretty easy depending on how the sensor attached. That part I want to duplicate.
Calibration for different attachments could be easy, as long as you didn’t overthink it. I want to duplicate that too.
I don’t want to look down at my phone when I’m working. I want to look at my attachment.
I don’t want to have to remember to charge it or replace batteries.
There are other downsides to the electronic solutions, but those are my personal hot buttons.
Among voters there’s some interest. More or less what I expected in terms of percentages. Experts have lots of use time and develop innate skills. Some of us will remain amateurs because of our use patterns, yet we’d like to be more effective when we do use our equipment.
But those of you who vote no and explain your reasoning have brought valuable insight, and it is most appreciated. You are why us amateurs hang out here.
I’ll share when/if I have a prototype. If it does nothing but inspire a few people to roll their own, I think that’s a win.