What do you do when the nozzle is so big that it hits the opening of your ear canal and you simply can't get deep enough fit with regular tips? Small triple or dual flange or a spinfit twin blade? Regular spinfits help with the seal but for me they take away too much from mids, treble and reduce the size of the soundstage considerably.
My T2's are lacking almost all of the low end because of poor fit caused by the 5,5mm wide, straight, short nozzle. Also need to bump up the volume way higher than with any of my other iems. IT01 has the same 5,5mm width but thankfully the different angle allows me to get a proper seal with starlines, still need to fiddle with them from time to time if I'm moving around, though.
I wish all of them had the Tennmak Pro/Shure style fit