Part of that will be mitigated, but there will still be a small hitch. I tried fixing this, but do to various things in how UE4 works when generating the Unreal resources from the workshop file it has to be done on the game thread or it crashes everything. This means this part of it will still hitch. I’d love to move it off of there, but I have to touch some deep engine code to make that work from what I saw in my initial attempt, so that might not be feasible unfortunately.
On the bright side there’s also a small mem-cache for workshop avatars coming with this update (currently we only have a file-cache). So avatars previously loaded should load faster until you hit the cache limit. I plan to make that limit configurable in a future update. When nobody is referencing a particular avatar anymore I rip-down the UE4 resources, but leave our workshop stuff (which is considerably smaller) in memory preventing a read from your hard drive if someone starts using it again.