Calling 5x opens with 84s from the BB in a 4 way pot is profitable? Are you joking? Do you understand reverse implied odds? Do you understand position?

def add villain's flop bet sizing here to your mental notes on him

It's a 5 way pot and yes. If you're losing money in these spots at your typical 2/5 game then you probably have a lot of major postflop leaks in multiway pots.

Remember the call doesn't have to be +EV, it just has to be more EV than losing 1 bb (which I guess you could say it technically could be defined as +EV blah blah blah semantics). Even though this call is only marginally +EV this situation happens frequently so if you're giving up small amount of EV often then it adds up quickly!

pre could go either way depending on how spewy we feel

Biggest factor in this hand is V ripping $200 OTF into a $125 pot. What hands from semi-competent players actually take that line 5-ways on Q88? Maybe gutters with FD (JT T9 J9), super spazz AK, AQ, KK+ trying to protect?

You’re often going to struggle extracting value here from anything except AQ+ so I like checking and bombing river (nobody folds boats!) if checked to again, letting V bluff river with lots of garbage OTR.

the debate about speculative calls like this will rage on forever and can never be settled because the truth is it's entirely dependent on game conditions, one side will always say in certain game conditions we can call, another will always say there are no game conditions where it's a profitable call, in the end you have to know your game and make the assessment. having a blanket policy is probably a leak. i've certainly made some preflop calls that look lolbad on the surface but i can tell you unequivocally they were right in the game conditions. usually it's being extra deep with really bad players or tables where multiple rounds of shots have been had and guys' girlfriends are railing them, things like that.

when you have to adjust your standard open size from 4x to 12.5x because every hand is going 6 to the flop regardless, you can adjust your BB defending range.