I made a Unity Editor tool to batch-upload VRChat avatar outfits automatically
If you manage multiple outfits as separate avatar uploads in one Unity project, you know the pain for every upload you have to manually set one outfit to Untagged, hide all the others, swap the blueprint ID in the Pipeline Manager, upload, then repeat for every single outfit.
The reason to keep them as separate uploads instead of one big avatar is file size. One avatar carrying every outfit at once bloats the download size for anyone who loads you separate uploads mean people only download what's actually on you.
I built a Unity Editor plugin that automates the whole thing. You set your blueprint IDs once, and it handles the tag switching, SetActive toggling, pipeline ID swapping, and SDK upload for each outfit in sequence. It also supports per-outfit blendshape overrides (useful for things like heels affecting body shape) and restores your skin back to its original blendshape values after the batch finishes.
GitHub
https://github.com/TheSilentD3ath/VRChat-outfit-batch-uploader
Just drop the Editor folder into your Assets and open it under Tools → Shiro → Outfit Batch Uploader.