Sculpted Objects - Phantom & Linking

Hi -- noob builder here with a question I can't find the answer for.

I am building a simple garden trellis. The object consists of basic cube shapes for the structure and a sculpted prim on each side for the lattice.

Once I add the sculpted lattice to the side I can no longer walk through the trellis (some sort of invisible barrier cause the sculpted lattice).

If I make the sculpts phantom, I can walk through the trellis again but when i link those to the structure either the entire structure becomes a phantom object or normal object that cannot be walked through.

I've read tutorials about phantom objects etc... but everything i've tried doesn't create what i'm looking for.

How would I have the trellis as non-phantom and use the sculpty parts and still be able to walk through as a single linked object?

And... why does the sculpty have this large barrier around it? Does that always happen?

Sculpties use the bounding box like all prims. See it by pressing Ctl + Shift + R to go wireframe.

Unfortunately, they MUST be made phantom and transparent prims used to imitate solid surfaces. it's a royal pita.
You must link them separately or the whole build turns phantom.
Sculpts = phantom. The rest = normal.

The Opensim engine handles these fine and you can walk on sculpty stairs like you expect. I don't know why SL still has this limitation.