Marcin Borkowski (mbork) has a short post that brings news of an upcoming feature in Emacs: transient input method. It’s much like toggle-input-method used to switch to another input method but it’s only in effect for the next character. That can be handy if you need to enter, say, a LaTeX character but don’t want to stay in TeX input method all the time. Of course, you can always just toggle the TeX input method off again but that’s a bit of a pain.
I use the TeX input all the time. It’s usually because I want to use --- to enter an em-dash. That works without TeX input method but the Unicode character it uses messes up the RSS feed. The em-dash character used by TeX input method works correctly so I have to switch input methods to use it. The trouble with the TeX input method for me is that my key chords (as defined with the key-chord package) don’t work so I have to either toggle the input method again or use some other way invoking the function bound to the key chord.
Transient input method isn’t available in Emacs 27.2 so I haven’t had a chance to use it yet but it seems like it could really be handy much of the time. As Borkowski points out, transient input method is an example of polishing Emacs to make editing a bit more pleasant and once again puts the lie to the claim that Emacs is old, defunct technology.