These are the STL and STEP files I created for making my 6mm water jet cut aluminium frame for my Prusa i3 MK2s replica. I can't say I recommend the project in an objective way because it didn't make much difference overall, however it was a lot of fun.
This is the video where I built the printer and discussed some things about it.
up to 50% can help if you want to. More perimeters will improve strength more than infill though.