Despite all of this, I still regularly run into drivers who clearly don't see me. I'm lit up like a Christmas tree! The only conclusion I can come to is that a lot of drivers aren't paying attention. I think all the visibility changes I've made probably make a difference, but there's little I can do to for those who won't see me no matter what I do.
Acting like other drivers can't see you leads to particularly conservative cycling. I do often wait for a road to be clear if I'm going through a dangerous stretch of road, but this adds a significant amount of time to my commute.
The only thing I've found that works decently for drivers who clearly aren't paying attention is noise. I used to have an air horn, which I should start using again. I've been shouting as needed lately, which works but probably isn't good for my throat.
Even before I had a car with bluetooth capabilities, if I _needed_ to make a call on the road (which is already a very high bar), I would use the voice assistant to place a call on speaker phone and talk loud enough that it could catch my voice from the cupholder.
If you make eye contact with its driver, then maybe they've seen you. Otherwise, they can't see you.