The MBI assembly instructions blithely direct you to:
Using superglue, or ideally acrylic cement, you’ll want to attach the spacer feet to the bottom of the supports.
As it turns out, though, the tabs on the Support sides stand just a bit proud of the Bottom plates, so that any attempt to glue the Feet in place will simply attach them to the side tabs and nothing else. Not what you want…
So I rubbed the Bottom plates on a sheet of coarse sandpaper until everything was nice and flat:
Then the spacer feet glued neatly in place:
I tried to keep the acrylic cement off the tabs, so it’s theoretically possible to dismantle the whole thing, but I suspect that’ll never happen.