as a joke,
I made some TOFU Burnt Ends while doing some other BBQing,
they turned out surprisingly well,
I'd never choose them over a meat counterpart, but as an option, it wasnt bad
we got the extra firm TOFU
drained it, cubed it 1.25-1.5" cubes
placed on a drying rack for an hour or so to get the liquid out
coated in olive oil
then sprinkled with a basic BBQ RIB RUB on all sides
put on the grill on a rack while smoking the other food for about an hour or two to help dry them out
then tossed in bbq sauce and put back on the grill to glaze the sauce
everyone was surprised that they werent bad at all
good luck
I realize your wife isnt going vegan
but if you want to serve this to someone with restrictions on their diet,
make sure the BBQ sauce is Vegan as well