Many other reasons to be concerned about performance, but there's no evidence that they're withholding essential features like this from their free version.
The Sidekiq memory killer is enabled for both CE and EE by default with the Omnibus package. If you're seeing something different please let us know and we'll see what's going on.
The fact that it's acceptable to restart sidekiq instead of working on fixing the memory leaks in the first place is a perfect example everything that's wrong with software engineering in Ruby land.
Reminds me of the classic "The main Rails application that DHH created required restarting ~400 times/day. That’s a production application that can’t stay up for more than 4 minutes on average".
https://github.com/gitlabhq/gitlabhq/blob/master/lib/gitlab/...
https://github.com/gitlabhq/gitlabhq/blob/master/config/init...
Many other reasons to be concerned about performance, but there's no evidence that they're withholding essential features like this from their free version.