I am coming to Thunderbird from having been a long time user of PostBox (PB) -- which unfortunately has been sold to eM Client.
The Favorite option in PB had 2 function I much appreciated:
I have been saving my emails for more than 20 years, dragging from one client to the next. The result is that many of my folders have a subfolder called "Archive." If I favorite more than one of them, I can't distinguish which is which. On the other hand, having a favorite folder be able to have a drop down selection, resolves this issue. Amongst others.
While I have a number of favorite folders, some are more frequently used than others. Being able to put them based on my usage would be greatly appreciated.