I've noticed some Moto devices seem to have calmer screens. I will be taking a good look at them again soon, there is a new model being introduced soon. I will also look at the Nokia 8 but Moto is the one that comes to stores here. So I would say consider viewing Moto.
I looked at an LG G6 and V20 in the store this week and decided nope.
I also looked at the 7+, it seemed ok as well.
I'm still using the M8, but I'm increasingly becoming annoyed by something in it. It has CABC turned on.. content adaptive backlight control, this is what was freaking out people with the XPS 13 laptop when it was first introduced because the firmware to control it was in the panel itself and they couldn't disable it. CABC is not auto-brightness which is a switch you can turn off.. this is the software monitoring what is going on and changing the brightness based on how much black or white is on the screen. I can see it changing when videos change scenes, pictures too. CABC is in build.prop and the kernel. I haven't yet fiddled with build.prop to see if I can disable this behavior. I've just been procrastinating on it because my device is stable and I have a lot of pictures on it I have to move off before I back it up and then start messing around with seeing if I can stop it, and if not, checking GPE, LOS to see if they have the behavior. If I can fix it, I could see myself using the M8 for longer.. I mean, I don't use it for gaming so..
The battery is pretty fried though.. I keep a charger and cable at the office.