PumkinsAvatarTools VS VRWorldToolkit

you can use Pumkin's Avatar Tools https://github.com/rurre/PumkinsAvatarTools

well theres no reason to unpack prefab, you can add things without doing that, and if you want to re-order stuff do it in blender if you want to transfer things from 1 avatar to another in the hierarchy, you can use pumkin tools https://github.com/rurre/PumkinsAvatarTools

Does https://github.com/rurre/PumkinsAvatarTools contain stubs for Dynamic Bones?

Use Pumkin Avatar Tools. It can autoremove the physbones with one button

I recommend using Pumpkin's Avatar Tools in Unity instead. It has a tool you can use to easily play animations on models among other things. I personally found a Fortnite animation pack that I use to test my weight-painting,

What could be happening is that the animation is still in "preview" so if you go back to the animation tab below and click the preview button, it should release that pose and return to a T-pose state. If that isn't the case like most people suggested using Pumkin Avatar tools can also help as well. https://github.com/rurre/PumkinsAvatarTools/releases

Instead, find the .fbx file (or OBJ) that came with the avatar and put that into Blender, then use https://github.com/rurre/PumkinsAvatarTools/releases/tag/1.1.1 to copy thing over from the already setup avatar. Remember that while exporting in Blender, disable it adding leaf bones, it is in one of the drop downs when exporting.

If it is Dynamic Bones related, I see that Pumkin's thing here has a button to remove missing scripts. "Fix Missing DynamicBone Scripts in Prefab" https://github.com/rurre/PumkinsAvatarTools

OR (better option) download this, it's a helpful tool while creating worlds. After importing, go to the vrworldtoolkit menu and hit "setup world" https://github.com/oneVR/VRWorldToolkit

I've used VRWorldToolkit in the past with a lot of success to find which files are eating up the most space: https://github.com/oneVR/VRWorldToolkit

2) 100MB is a lot, textures tend to be really heavy so if you haven't done it already I'ld recommend to crunch your textures ("crunch compression" setting on the texture), the VRWorldToolkit Unity plug-in can be used to check which element takes most of your space in the final build https://github.com/oneVR/VRWorldToolkit

Crunch your textures (in the texture settings, there's a "Use crunch compression" setting), a room like that doesn't need to be 70MB. I hightly recommend the Unity plugin VRWorldToolkit https://github.com/oneVR/VRWorldToolkit, it can be used to see which asset in your world takes most of the space ("Built report" tab)

this unity tool can help with the optimization https://github.com/oneVR/VRWorldToolkit

If you haven't got it already, i'd highly recommend VRWorldToolkit.

https://github.com/oneVR/VRWorldToolkit/releases Add this to your project, enjoy.

VRWorldToolKit: https://github.com/oneVR/VRWorldToolkit