3-Whistle Mechanics Question

[RookieDude]

We are still working on the new 3-Whistle Mechanics implemented here in WA state.

Question:
Team A in their frontcourt. Trail, tableside has a foul in his area on A1. Now we are going the other way.
How do some of you do this...switch or no switch? (NFHS)
Does Trail stay tableside, at the spot of the foul, while Lead "long switches" down to new Lead postion?
If it is a bonus FT for Team B...does Trail stay tableside and Lead administers FT at the other end?
Or does old T go to new L and old L becomes new T?

I had a couple officials ask me about this...and wanted to make sure I told them the correct NFHS procedure.
One of the officials wanted the old C to become new L and administer the FT's and the old L take new C in Team B's Frontcourt. I advised him that is not how we pregame this situation.
Comments?