Buttons gotta be covered, and be big. Sleeve pockets I like vertical zippers (ala Arcteryx Recce shirt or CPgear OTW shirts)
I wear my brit smock hunting, so non tactical but noise discipline is important. Ungulates are nervous critters in hunting season, and aint as dumb as they seem. Buttons win over velcro.
Typically, for me, if im going into my smock pockets its to use an item needing dexterity (compass, pen) or removing or adding hand/neck layers (merino glove liner, neck gaiter) so I wouldn't be wearing mitts anyway that would prevent opening and closing a button