You're better off going wit's end than giving up a summ and buying null stat items as squishy early game Gnar. Yes, I actually think wit's end is pretty solid enough in the right lane.
I kinda want Gnar to not need frozen mallet anymore. I was doing frozen mallet fervor Gnar before any Koreans or Darshans and while it was pretty fun for a while having my own OP strat it's old and mainstream now. Beating up stuck slowed targets loses its fun eventually.
I feel like not building mallet either first or later on Gnar is simply a waste. I just want to make room for a more variable offense item every game.
It's really difficult to make FM not exist and then buff Gnar though because the utility of the mallet cannot be replaced onto mini gnar without going overboard. The item lets him make great picks and duels and peeling mini gnar would otherwise have much more trouble doing.
Having the mallet ensures he has a strong strategy at any time regardless of rage (small form look for small fights/duels/skirmishes| big form go group look for wombo combos), it's just.. no level of champion buff can fairly replace FM
But as I said, fighting and killing perma ensnared enemies eventually falls off the highlight list.