Fractal HD Grommet

I recommend printing them in rows of 4, attached by a brim.

Ideally use the softest TPE you can print for best dampening (I use 85A currently); most TPU might be too hard.

For Fractal Whoop frames screws I recommend M1.7x10mm, self tapping, wide washer, flat tip such as these: https://s.click.aliexpress.com/e/_DliSpHf

Else you may get them with the prints from the shop: https://store.fractalengineering.net/product/hd-hardware-set/

You could also drill out the bottom plate and use M2, but it's significantly heavier and I do not recommend it (also breaks your lifetime warranty, for real 👀)
 

On Wingman just use the included M2x10mm stack screws, they should tap into the grommet nicely