D&D had a significant broad revamp aimed at tuning down magical items since the the second edition (i.e. a "+5 Carsomyr" would be a +3 in the fifth edition).
And some weapons in BG2 were ridiculously powerful EVEN by second edition standards. Especially in Throne of Bhaal where it was basically a slugfest among gods and "ordinary" +3 weapons were dismissed as vendor trash.
If they even decide to borrow some extremely powerful artifact from the previous games, don't be surprised to see their values slightly tuned down.
+6 was a thing, among other unspeackable features like "set str to 25", 10% chance to instakill, dispel on strike.
but still names and flavours are all i ask, nobody really wants Carsomyr to be back as it was
