Regardless of where they are in the MSQ they will gain a
substantial boost in power if they updated it though

.
Especially in context of fighting dummy targets or open world monsters, which was part of their example in their second post in the thread. So it seems it's not simply a misunderstanding of potency math they've issue with, they just don't do that much damage in general- having updated gear would give them a huge boost.
I know they've tried to update some gear since they've some level 49 stuff, but that's what I was trying to tell them in my first post- that at the turn of levels particularly at intervals of 10 (50, 60, 70) there is equipment that will boost significantly from where they were (difference from level 51 gear to 53 is nothing like the difference from 49 to 50 or 59 to 60 gear), and also to be careful of new content at the turn of those levels because if their gear isn't updated it could feel like a sudden wall smacked them. Like those who try to do Kugane's Castle while still in basic level 60 gear, getting ripped to shreds. Augmented (tomestone) gear will take them into the next levels very well, but if they had level 49 gear trying to do level 55 content, it might not feel as nearly as smooth as having nice 50 doing 55.
Also we do know they're past the magitek walker at least, since they've that as one of their mounts.