do I need to take off the lens protector before putting the action 4 camera into the dive housing?

no need and plz do not do that.
WITH lens protector on , action4 is waterproof.

my personal experience is that :
when dive housing smashing on reef or sth, action4 self waterproof is another protection.

DJI-ytao Posted at 8-16 19:52
no need and plz do not do that.
WITH lens protector on , action4 is waterproof.

got it, thanks

Hi there. Thank you for reaching out. Are you pertaining to the waterproof case? If yes, there is no need to remove the protector when using the waterproof case. Should you have other inquiries, please don't hesitate to reach us. Thank you for your valued support.