More reliable loaders

**Describe the bug**
If I checkout a branch and and it takes a while, sometimes the loader doesn't appear, or if it does appear, it doesn't appear to spin. There's no good reason for this: I assume something is happening on the UI thread that shouldn't be.

**To Reproduce**
The way I reproduced this was by going to a huge repo and disabling the commit limit in the code so that the checkout took a while.

**Expected behavior**
Loader appears and spins without lag

**Version info:**
commit=1f8e838052a1bc083cb50560431b2f115df8acb6, build date=2023-05-23T12:54:57Z, build source=unknown, version=1f8e8380, os=darwin, arch=amd64, git version=2.33.0

Note: This bug is not about adding _more_ loaders in more places. It's about fixing the behaviour of a loader when it appears