‘Make sure you don’t spend more than 5 minutes on your thought downloads each day’

Dear Brooke,
I read this as the response to one of the questions you answered either yesterday or the day before.
Why should we not spend more than 5 minutes? I can do easy up to 30 mins of thoughts but I am really dialling in my thought download practice after 9 months in scholars. Is 5 minutes what we work down to? Or is there a good rationale for not giving in more than 5 minutes even now when dialling in?
Thank you so much!