Hi… It looks like that’s not only allowed but actually rather encouraged/common:
My impression is that it was even one of the original motivating cases (along with security-firm clientele) for the product, although I may be wrong there…
Also, this older blog post pre-dates Sprites, but it gives an idea of Fly.io’s overall perspective on such things:
Our Best Customers Are Now Robots
(As far as I know, that general tenor hasn’t changed any.)