For constant-profile tunnels such as TBM tunnels- then adaptive families are your best bet. To resolve the gap/overlap issue, then the easiest way is probably to nest a void family.
I’m not quite sure what you mean- but as far as I know, an adaptive family can only be given a category as shown below- not structural framing
You can put structural framing families along a 3D curve- say using StructuralFraming.BeamByCurve.
