I do have a magnetic stirring hotplate I got for my darkroom. I tried it once for shellac, worked pretty good but decided it was way easier to put the flakes into the alcohol in the bottle and forget about it for a week dissolving completely.
I bought one of these a few months ago to use in my darkroom where I do a fair amount of DIY chemistry for developing film, paper, etc, and often have to combine things that can take hours to dissolve.
...and one of the first things I used it for was dissolving shellac flakes in denatured alcohol