i'd say it depends. fullring i'd go 4bb from 1-2, 3bb from MP to CO and 2 or 2.5bb from BU. that's because we have a super strong range from UTG and since most ppl will probably be setmining nits they will be just donating their 4bb to us whenever they call and miss etc.
for SH i'd just say 3bb from all positions except for BU, where i'd minraise it as a standard. wider ranges in SH and super wide range on the BU so we adjust our sizing accordingly.
there is always the flip side to these arguments - yeah you get to bloat the pot more with a 4bb open when we hit something, but the other ~66% of the time when we miss? sure, we cbet bluff... but it isn't so fun when the fish don't like to cooperate.
i guess the fact that you have different ppl saying different things means it isn't going to be that much of a mistake if you make it 3 or 4bb pre, as long as you understand why and you have a plan and your sizing reflects your ranges.
if there is 1 limper, my range changes. if there are 2 limpers my range will be different from if there is 1 limper. if there are 3 or more limpers it starts to really change the sort of range you should be isolating with - we want a stronger range when there are more limpers, so 7bb might not be as overkill as you think.