Here are from my point of view two functional solution, ratchet or silent blocks. To be honest Iam surprised why silent blocks are so unknown solution. It was on my engineering middle school one of solutions which I remember til now. Check 2:15-2:23 in this video
Advantage of this solution it is that You can choose 3 x big silent blocks for layouts like on Trampa or Apex deck or You can use 4 x small in square layout like I did. Both will perfectly work. Next point is that compared with bushings and screws combinations, silent blocks will not jamming holes in battery box. Silent blocks are standardized engineering parts in 4 basic types. Nut-nut, screw -nut, screw-screw, and just screw if Iam not wrong. Both sides are connected just by rubber, thanx to this silent blocks eat lot of vibrations. Hope it was helpful.