This again is a limitation of mapping labels to IMAP, which does not understand labels.
Both the Gmail web interface and the Gmail API allow the ability to set all the labels for a message. This can effectively enable your desired functionality. But IMAP can only deal with "folders", and cannot correctly decide when to remove a single label or remove all other labels when it sees a move action.
IMAP also only deals in messages and not threads. Gmail labels also technically only apply to messages, but the web interface shows the union of all labels of a thread. This is another decision I agree with. It means that when someone explicitly adds me to a thread, the whole thread gets highlighted in my feed.
I personally really enjoy the Gmail/fastmail/proton behavior so please don't make another political campaign to make things worse again. We have enough of those.
Both the Gmail web interface and the Gmail API allow the ability to set all the labels for a message. This can effectively enable your desired functionality. But IMAP can only deal with "folders", and cannot correctly decide when to remove a single label or remove all other labels when it sees a move action.
IMAP also only deals in messages and not threads. Gmail labels also technically only apply to messages, but the web interface shows the union of all labels of a thread. This is another decision I agree with. It means that when someone explicitly adds me to a thread, the whole thread gets highlighted in my feed.
I personally really enjoy the Gmail/fastmail/proton behavior so please don't make another political campaign to make things worse again. We have enough of those.