The linux world solves this same issue by not strictly following SemVer, having a pkgver and a pkgrel; eg 1.2.3-1 and 1.2.3-2 have the same content but have different packaging informations, or package release. Those are not prereleases, just different repackaging.
Technically, it is possible to have four-segment non-semver package versions that ignore non-compliant parts in semver (M.m.p.r)
Personally, If everything else fails, I would just add the re-packaging appending the release to end of the patch (M.m.pr) 1.2.30, 1.2.31 etc.