Sorry that it took so long to get back to this. It looks like commenting out those lines in view_workingtree.py fixed the issue with file locking.
We also had a problem with opening a project with a large number of files/folders (over 10k) over a network share, which would cause bzr explorer to stop responding. Commenting out the QFileSystemWatcher lines also fixed that problem.
Sorry that it took so long to get back to this. It looks like commenting out those lines in view_workingtree.py fixed the issue with file locking.
We also had a problem with opening a project with a large number of files/folders (over 10k) over a network share, which would cause bzr explorer to stop responding. Commenting out the QFileSystemWatcher lines also fixed that problem.