In project delivery, consistency and predictability are far more important than explosive effort. Beware the hero developer, praise the one that chips away diligently each day.
Good design, requirements, thought takes time to emerge and it can only emerge through progressing steadily, shipping, sharing. “I just thought of something” happens over days, not hours.
The BA that writes 3 new stories every day is far more valuable than one that “smashed out 16 stories on Friday”. Yes the latter has had more output, but it can’t be digested, thought through and all the gaps, edge cases and improvements identified.
These things take time.
As a lead/PM/Scrum-master you should ask “do you have enough time do finish what you need to”, not “do you have enough time to do this extra thing”.
Ship in small daily chunks, socialise it. Write a 1 pager that explains it all. Keep close to the who needs to know it and speak with them frequently.