For self-hosting, have a look at what we're building with SlicerVM.com (disclosure: I'm the founder). Also runs just as well on Apple Silicon.
We run quite a few Slicer instances on mini PCs and Ryzen builds - also on Hetzner (and yes ouch 120 EUR / mo up to ~ 550 EUR / mo for 16core / 128GB RAM feels almost unfair)
Interesting. How does this compare to Firecracker? Also PhoenixNap looks really interesting. Do you happen to know if Linux software compatibility holds up on Ampere? 80 cores for $400 a month seems pretty good.