Simagic Alpha base mount for 80x40 aluminum profile. I designed this mount to be printed in PLU so that it absorbs the vibrations emanating from the base, which cause loud noises in my rig. I would recommend a infill > 40% and 3–4 walls.
Screws bottom m8, screws into base m6.

It should also fit for the new Evo Bases, 5cm. Maybe you need to cut off the inner support, where the old Alpha Base fits in.

Update: Every plan brakes if it comes to reality. The flex left/right, rotation left/right were goot but there is too much flex in up/down.
I add a version with solid walls, TPU and support walls does not work well.
I add damper pads, so you can print these in TPU and the base mount in e.g. PETG.