I've seen that article before but I'm not convinced. Haven't found anything like that mentioned literally anywhere else on the internet (I thought it would pop up in articles about EV batteries which have hundreds of cells).
There is a chance one of the packs constantly sees higher temps; the...
IMO there's very little difference between a 4s in a single pack and 4s in two packs connected by an extra wire (namely, a miliohm or so of resistance in the middle). And I never heard a reasonable scientifically backed explanation on the difference between a cell being the first vs last cell in...
I'll bet you could use xt60 for everything, not ideal, but I've seen 1/8 4s buggies use deans 🤷🏻♂️
Give xt60s a run and if they get hot, switch to xt90s.