Can these be made as tofu "meat"balls and cooked in sauce?

Not likely.

I've cooked a lot of tofu in my lifetime and the cornstarch in this recipe isn't going to do enough to bind the mixture into something suitable for your ambitions.

Your best course of action would be to shape into small cakes or balls and pan fry them. Then gently submerge them into the sauce for a few minutes.

It's worth pointing out that the author himself warns against grilling the raw patties (lest the patties fall apart into the grill). He instructs to bake the patties first then grill to get some char marks.

The point is to harden up the patty surface so it has some structural integrity. If you put the raw "meat"-balls into a sauce, my expectation is that it would simply break apart since there is nothing holding it together.

You may consider seeking out other tofu "meat"-ball recipes, see how those utilize a binding agent to provide enough structural integrity and consider using one or more of those strategies to provide more solidity to the above mixture.

Best of luck.