@hamkg
I think the problem you are experiencing is not specific to FamilyTreeView, but is a problem with Gramps itself (apparently the Addon Manager). I kindly ask you to continue investigating this bug in a separate thread (or head directly to Gramps bug tracker). That way, people experiencing this problem can more easily find your investigation, and people reading the FamilyTreeView feature requests can more easily find the FamilyTreeView specific comments in this thread.
You can ask @emyoulation if he wants to move your comments that are not related to FamilyTreeView to a new thread if you want to keep them in your new discussion.
That being said, I definitely encourage you to post feature requests and bug reports related to FamilyTreeView here or as an issue on Github!