More about the PC: https://www.reddit.com/r/sffpc/comments/18qka9x/passive_rtx_4060_build/
As the heatsink can reach over 60C, PLA or even PETG will probably get too soft and creep over time. Use some filament rated for high temperatures.
I used GreenTEC Pro Carbon. After 3 days of use, the top GPU mounting bracket made from unannealed GreenTEC Pro Carbon yielded to the high temperatures.

The author marked this model as their own original creation.