Yeah, it's absolutely doable, and I'm totally in favor! There's literally no downsides to having this as an option.

Also, it sort of goes without saying that this would be optional... Forcing people to state their pronouns when they aren't comfortable doing so is not okay, and would go against the whole point of this suggestion.

When this is implemented, I encourage cis users to also use this feature if they're comfortable doing so. I'd love to see this help normalize stating pronouns in general, instead of just becoming a way to tell which users are trans.

(By the way, there is no need to make the distinction "NB/trans" because nonbinary people are trans, so just saying "trans people" already includes them :) )