1) What happened?
When opening a project larger than 20GB that is synced with Collab, a "Checking for changes" progress bar opens that effectively doubles the amount of time it takes to open a project. This is because Collab is looking through each file to check if any assets have been modified outside of Unity's scope (ie. the File Explorer/Finder, Visual Studio, etc.) and, by extension, Collab's scope. This check is linearly related to the size of the project and startup times are only made worse the bigger the project becomes. Some projects that are over 50GB take hours to open when Collab is enabled.

2) Repro Steps
1. Open a Collab-enabled project on any version of Unity older than 2017.1 that is larger than 20GB.
2. The Editor freezes while the project finishes importing all assets.

Expected: The Editor unfreezes and the project can be interacted with by the User.
Actual: The Editor remains frozen while Collab's "Checking for changes" prompt appears and doubles the startup time by seeking through every asset in the project for untracked changes.