Usually if frap roast runs out we use espresso shots so 1 for a tall, 2 for a grande, and 3 for a venti

you could probably ask if they want shots in there instead?

I would offer them shots and not charge them for it tbh

Espresso or cold brew

Use espresso shots: 1 Tall ; 2 Grande ; 3 Venti

Cold brew

I'd use a Via Instant coffee from retail section. But if it needed to be from behind the counter?
Definitely cold brew or make a batch of ice coffee with half the water normally used for a more concentrated flavor, kind of like how frap roast is.😎

Espresso shots

Dark roast