We have this little nugget here but I agree it is a bit buried down, will move this to main docs: https://github.com/getsentry/onpremise/tree/20.9.0#updating-sentry
Short answer: no. You need to upgrade to 9.1.2 first.
There’s this community project: https://github.com/sentry-kubernetes/charts/ (note that this is not official and we do not actively support it while we appreciate the effort and attention to detail there)
Nope, it is quite minimal compared to anything that comes later: https://github.com/getsentry/onpremise/blob/84861509ae097c11892d29da4739a4758bcc8a84/docker-compose.yml#L31-L49
That said this means you don’t have any of the advanced capabilities like improved search, performance monitoring, discover etc.