As of v1.1.2 of Unalloyed, I'm confident that the majority of the commonly encountered bugs with installation have been ironed out, and I've managed to get randomization to work for even the latest (as of this post, v0.4.53) version of Reforged.

Going forward, I'll make periodic updates to increase the "supported" version of Reforged, but even if you install the modpack with a version beyond the recommended, Unalloyed will detect this and perform a "clean" installation, meaning all map and event edits will be purged, save for common files. This should allow randomization to work regardless of the version used.