Those solder joints and finicky little wires seem much too fragile on their own:
This should help:
Foam blocks hold the ribbon cable in place and provide a bit of strain relief around the hard plastic edge:
The brass inserts in the bottom block (on the left) got epoxied in place, because they must provide quite a bit of force to clamp the foam. Their larger knurled end sits flush with the outside surface and the smaller end has one thread thickness of clearance below the inner surface.
A last look at the wiring:
I think the preamp must sit at some distance from the antenna to prevent feedback, but that remains to be seen.
The M2’s nozzle accumulated a huge blob of PETG that turned into a giant smear:
Fortunately, it’s on the inside where nobody will ever see it. If you know where to look, it’s barely visible from the outside.
The solid model shows off the structure a bit better:
The inside view:
The OpenSCAD source code as a GitHub Gist: