A buff to weak perks: Optionable 5 perks (only if 2 of them are underused).

An easy way to buff the most unused perks (for killers and survs.) would be to make the last perk, either 1 "normal" or 2 "weak" ones. So you can keep playing with your usual 4 perks or change 1 of them for 2 of the underused ones.