ᐅ The roofing underlay has small holes. Is this within the acceptable tolerance range?

In my view, this is a defect. Such a membrane must also be overlapped and sealed to reliably function as a "second waterproof layer," meaning without leaks. How is that supposed to work with this number of holes?

Or is the metal roof 100% snowproof and rainproof?

At first glance, I would also say that this is a defect, as the holes appear to be quite large.

Holes must be sealed with appropriate tape. Please note that otherwise the warranty from the supplier of the underlay membrane will be voided.