I would report these guys to Gov. to see if their claims can be
verified. If their claim was true on R value then multiple layers would
help. R 56", I know of no product of R 56".

R 7.2" is the highest I know of for insulation, foil faced
Polyisocyanurate, and it settles after outgassing to near R 6.2 per
inch.

It is like Insulating paint and Reflextic, No independantly verified
testing has been done by a certified lab. Id say snake oil.