Soundfonts - Being able to reassign sounds to an instrument/changing names?

Apologies in advance if this has already been covered! So, back in Musescore 3, you could assign a sound to an instrument regardless of what that instrument was. Due to the new interface and no synthesizer any more, all you can do is go onto the mixer, click 'soundfonts' and whatever sound is assigned to that instrument is the only sound you can use for that instrument.

In most cases, it will be the appropriate sounds but sometimes for certain purposes, you may want to change the assigned sound (example - when using outside soundfonts that needed it for techniques that did not play them automatically).

Obscure/uncommon instruments that may not be 'part of musescore'/ in the instrument list, being able to control the specific sound for that instrument via the mixer/synthesizer was a lot easier because you could also rename it if needs be.

In the picture below, the mixer just lets you click on the soundfont assigned to that instrument so it will be an automatic selection of the actual 'sound' for the instrument which you can't change because there is no way to do so with the way it is set up. At least, to my knowledge thus far!

Does anyone know if there is a way around this for obscure instruments/ or being able to reassign a sound to an instrument in a score for whatever purpose we need it at the time?