I prefer Gitlab for private installs, but the community edition lacks many critical features that are only present in the paid version (export/import of issues, I'm looking at you)

Yes, but there are multiple open source tools that make this easy and they have an API for it as well. I think the need to have a large monolithic platform for issues is absurd. I probably won't be using GitLab or GitHub for my next project. It totally defeats the decentralized nature of Git.

So.. where do you keep your issue tracker? The bitcoin blockchain?

Maybe you're talking about something else but according to the features page [0], both importing and exporting issues as CSV is enabled for all versions of gitlab.

[0] https://about.gitlab.com/features/

As other users noted, this feature has recently become part of the community edition. They are currently in a rolling effort to move stuff from paid to free.

You should really check GitLab out again if the last time you used it / upgraded it was one year or so ago.