Trackstanding is a useful skill. It's not essential in itself, but it is part of being in complete control of the bike. If you can do it, you'll also be more competent in other bike-handling.

OP, if you can more or less do a seated trackstand (you're right, it is much more difficult seated for most people) for a whole red light cycle despite having had a stroke, I'd say you were doing better than fine.