It's the figure hitting the bubble that causes the cracked damage in transit. We are taking about a regular stress in transit like a box being dropped or waved. Nothing would save it if Postie actually sits on it
And both approaches have merit.
Either make the whole MOC move in a controlled manner with single MOC in a large box full of styrofoam beads. This does not work with MOCs in acrylic case or in star cases. In that case force transmitted on the figure is multiplied with the weight of acrylic case. I think this is what Section8 suggests.
Restrict the MOC in a traditional way but pad the bubble in such a way that there is no give when the figure strikes it. I got a trilogo Barada from Sweden and the seller had cut a precise well in the styrofoam tray in which the rather fragile bubble fits snugly with no stress on the plastic.
This R2 unit has a bad motivator.