Plushtrap has already been updated an re-rigged in Blender 2.9 and Nighttrap is undergoing that process as I write this. Thankfully, plushtrap no longer has any porting issues when importing him into UE4. I'm hoping that Nighttrap is the same case. After a two-year roadblock, things are finally seeming to get back on track. Here's to hoping that the others are the same case as Plushtrap and port properly once updated.