Oh I can relate, but I can see that you're already thinking of the right things. Riding with the low sun at your back you ARE virtually invisible, and it took me a few near misses at one certain spot on my morning commute to realize that... There was one roundabout where at a certain time of day I had the rising sun right at my back, and I hadn't noticed until I turned around to check for myself. Couldn't see a thing. From then on I simply rode as if I were impossible to see at that particular point. It goes against the "be visible"-creed, but you can't win against 10 000 lux or whatever it is.

I also ride as if any car ahead of me or beside me WILL do a right turn and cut me off. That means I either speed ahead or pull back a little if there's a bike lane, or take the lane a bit more if there's not, when approaching an intersection. Most of them never do cut me off of course, but I don't even get into the spot where I would be squished if they did.

Cars crossing from another direction are harder to predict, and every now and then somebody will just behave like an idiot. Making eye contact helps.

It takes a little thinking, but it does help imagining how you look from a drivers perspective, on every point along your route. They're looking for large fastmoving objects with bright lights, we're small, slower and often darker with less lighting. An obnoxiously bright blinking light and a high-vis jacket will make you more visible and most important, more noticeable. But you still will be invisible in certain situations.