Mate-screensaver black screen

there are 2 keybindings

Yikes there are too! But mod (windows logo) is not a setting I can see in the GUI
Thanks for reporting that one

I am on a tower and I have looked at my power management options and none seem relevant.

Now if you are interested, for your laptop, you can make a init type script that can automate what ever you are doing
try.....its not a screensaver example but I am sure you will catch on quickly

if you are struggling....I or others might be able to help
copy and paste your manual commands so we can duplicate your efforts

cheers