"Bayonet Fighting" (or something)
Ranged weapons are also considered Melee against enemies within your Point Blank Shot range
The point of this would be, at the cost of a feat, characters with could use Melee-specific attacks with their ranged weapon. Weapon-specific attacks (like Dagger attacks in VKF or Staff attacks in TA) would of course still be disallowed; only "Melee Attacks" would be enabled. Anything player-centered would remain player-centered, only the on-hit effects would extend out to the target.
I think this would open up a lot of interesting possibilities for ranged builds that are currently less than optimal (ranged EK) or just straight up dont work (Bowbarian). It would also make sneak-extending enhancements like Mech and DWS more valuable. Or, alternatively, it could just be a permanent "melee range" limit, but I think its better if you allow Sneak range to boost it. I dont see any potential for breaking the game either, considering ranged and melee already have comparable options in terms of powerful attacks.