While reading more about this I found out about the ~/.hidden file which I'm pretty excited about. The following hides the folder from Thunar & Dolphin (and presumably other file managers):
echo snap >> ~/.hidden
But sadly `ls ~` will still show it.
Question is if those user/mount namespace tricks are composable
As far as I'm aware, yes! You should be able to nest namespaces and mounts.
I was wondering the same. So infuriatingly obnoxious!