Around 210/215C looks about on the money - as is typical for most PLAs these days.
I was thinking 195-200 on the 2nd sample, as long as layer adhesion is good. What are you seeing that I'm not? Seriously; I'm looking to learn here.
The increased resistance to flow at the lower temperatures causes the small pointed tower to under-extrude a little (it's not much on those photos, though). Also you get reduced layer adhesion and, IME, a little more sag on the bridging (angle in the photos can make this deceptive though) as the first layer sags from the heat of the next layer going onto it. You'd think printing hotter makes that worse, but it sticks better, so if you have adequate cooling it seems to come out better.
What's really interesting, and very hard to get photos of, is the difference in appearance with temperature and cooling. That can be fun to play with. Generally cooler gives you a matte finish, hotter glossy.
If in doubt, print a little hotter, IME.
I'm still struggling printing the first disaster I had, not sure what Cura setting I'm missing, just tried again and stopped it due to this
Haha (sorry, laughing with, not at), now I see the problem.
You're not meant to print that on its side! You're extruding into open air. Get the bottom on the build plate and you'll be fine.
AMZ3D is.. not great filament, sadly. From Amazon I'd suggest eSun (sadly thoroughly out of stock currently), Prima, and maybe the latest line of AmazonBasics (I haven't tried the new stuff, though).