Should i leave it on let 3d application decide?
Yes. I have never changed default Windows settings on any of my systems that I can remember. One of my top computer ideas to use is "don't try to fix something that is not broken or you are likely to break something". Leave things at stock settings, unless you have issues or things are really not working like you think they should. Then research for a while why something does not work properly, then try some small things one at a time to fix that. Just looking to change settings before using the system is only asking to have things crash or do something odd before you even start.
Usually we see posts like this: "I just built a new computer and changed the thermal paste and...