So I'm modelling the concept and I'm looking into what the actual dimensions of the panel is. I didn't find that, but I did find out that the 3.5" screen is probably some of the oldest OLED around.
The 3.26" screen has the expected high contrast, but I don't think I'm going to be able to cut 6mm from the length or 3mm from the height because of how tight everything already is.
The good news is that the seller of the 3.5" display also has a 3.47" display. The bad news is that it has a lower resolution.
The good news is that it has a useful feature that sounds like it could be used for AOD.
Also, I though 198ppi was good, but then I checked the ppi of the low resolution 1.54" screens found on earlier android watches:
[about 5 minutes later]
I just found out that the 360p AMOLED was used in the Nokia N8 (source), which makes me think that it was the same OLED used in the Nokia E7 which I own (because I wanted to take notes with it, but working with only 2 thumbs is slow, hence #Tetent Tiny [gd0040] ), and if that's the case then the low power mode makes sense because the Nokia E7 had an always on display and was some of the best in OLED technology I've ever seen. I heard Nokia put some coating on the screen for even deeper blacks, but citation is needed.