More Fine Grain Control on Issue Number, for Import and Numbering

Description including problem, use cases, benefits, and/or goals

I'm migrating a few larger projects from an existing (happens to be a Redmine) project and scm tracker into GitLab. I have a moderate quantity of issues that I would like to import to the project on my GitLab CE server. ~"feature proposal"

Proposal

To have fine grained control over the issuance of issue numbers for a project, allowing for the import/creation (API) of issues at a given number (provided no conflict).

Links / references

None known at this time.

What I tried: I have tried creating the issues on my GitLab server via the REST API, attempting to set/override the issue number; this yielded undesirable results (everything but the issue number came in). Even if this worked, I would still look to number new issues under the according sequence (e.g.- after the last issued number). My attemptsused a personal access token, the JSON API, and iterated a CSV I was able to export from my existing tracker.

I asked on twitter if anyone knew of how to make it work (as it is today), and the GitLab account helpfully replied, but that it was not currently an option.