The Commit button might be grayed out if no commit message has been entered.

So you want to have a "Kill Git Process" feature?

> Someone has committed something which should really be two or even more commits.

For that usecase SmartGit offers the Split Commit command.

Such a search/filter input field exists for the new Standard window in 22.1 ("All Branches + Tags" section) and in the Ctrl/Cmd+P popup.

Would an optional colored bubble be a better alternative?

Did you already try to configure the Tag-Grouping in the repository settings (Repository | Settings)?

Please consider to vote for this issue: https://smartgit.userecho.com/en/communities/1/topics/1474-

There is such an option in the Branches view's hamburger menu.