[lasereyes136]

All work has a cost including documentation. You either make updated documentation an explicit work item or it will, at best, get done ad hoc, at worst, it will not be done. If you allow urgency of code requests to bypass a documentation requirement expect documentation to fall behind. If you expect the team to create documentation without explicit time to do so, expect it to not get done.

It is either a priority to do with time set aside to do it or it isn't, and you get what you get. Even a time-box, best effort documentation effort is going to have a better result than "hoping" it gets done and making it a lower priority.