I will provide another perspective. What's to gain by making the repair with spray foam at a professional level repair?
Strength is not part of this, as any repair will not regain or add any strength from what was originally in place. Insulation R value? May be.
Look at the other features of your TT. Windows and underbody for example. Do you reall think this small area of repair with or without insulation will make any difference? Odds are...no.
Make the repair, use a can of low expanding foam in a can for $4, or pack the are with fiberglass. And be done. You, nor anyone else will know the difference.
