The partial solution is to fix the selinux context as I noted on stackoverflow and github. But the real solution needs to be a selinux policy. Ideally that would be created with input from RStudio developers who understand its functionality.
Fedora acknowledged my github request for a targetted selinux policy, but given how niche RStudio Server is, I think it needs to be driven by its users' and developers' initiative for any real chance of being implemented.
Ah I'm sorry to hear about the difficulty you have run into here! I can definitely resonate with the desire to have a less-than-completely-open SELinux policy specifically for RStudio Server. Am I correct in understanding that this would be a policy that articulates exactly what system access the RStudio Server needs to function? (minimally sufficient)
Do you have any examples handy of how other software vendors provide this type of policy? Is it operating system agnostic, or specific to each linux distro?
Sorry for all the questions - I know very little about SELinux in practice 
I think it would be really nice to have this type of thing, but I'm not sure how much work it is / what its priority is / how technically involved it is / etc. I think scoping those types of things could be helpful to a resolution!
EDIT: Related GitHub issue: Support SELinux via configurations and documentation · Issue #4937 · rstudio/rstudio · GitHub