I run outsourcing agency, we work with US clients and have seen lots of fake applications (different degree of sophistication), so far we have either rejected them right away, or we were able to filter them during (remote) interviews.
That's exactly one of my use cases, I have setup runner for 2 projects last week and action runtime went down by a large margin, from 10-15 to 3-4 minutes.
I use single dedicated server that costs ~40EUR/month, AX41-NVME, and each runner is a separate user account to allow for some isolation.
Depending on your setup, you might need to spent some time adjusting jobs to have proper setup/cleanup and isolation between them (but it's not really Hetzner specific, just general issue).
I run outsourcing agency, we work with US clients and have seen lots of fake applications (different degree of sophistication), so far we have either rejected them right away, or we were able to filter them during (remote) interviews.