Really needs a small buffer between transitioning from movement to casting. wignitia dignitia...
Or at least alternatively, and perhaps obnoxiously, both exclude movement keys from being typed and have the letters in WASD never appear in a spell.
Bloody annoying and the source of 90% of my miscasts. Either of the above solutions are superior than this.
(Was glad to figure out arrow keys work, at least, but then some actions requiring mouse input are a pain. Not to mention the issue of your right hand being out of position for typing.)