I wanted to update this tread with my learnings.
Switched to Owner Weedless Wacky hooks in 1/0 size.
The Gamakatsu weedguard seems to work a tiny bit better when it accidentally gets thrown into a tree branch. That said, I've only lost one Owner hook due to snag.
The Owner hook isn't a cure-all to my hookset problems. I lost one fish (see below), but landed 4.
Owner weedguard seems to keep its shape and stay glued better. The Gama ones only last about 3-4 fish before weakening/ungluing.
I'm still testing rubber bands versus o-rings, but o-rings currently have the edge.
Perpendicular hook placement with rubber bands = 2 fish
Parallel hook placement with o-ring = 2 fish
I've lost three senkos due to rubber-band failure. One the bands snapped on hookset. A fish pulled the senko out of another, leaving band and hook. Third one snapped during cast.
With old Gama hooks, I lost several o-ringed 4" senkos. With the looser o-ring fit, they seemed to just work their way off the hook. I haven't experienced this with the Owner hooks so far.
As most have noted here, slack management and hookset technique have been the more/most important factors.
I've been practicing (while standing on bank, sitting on bank, and in kayak) counting to 3 as I reel up slack with tip down and then lifting or sweeping the rod tip. This has proven successful for the 4 wacky senko fish, as well as the numerous other fish I've caught the last few weeks with open-hook wacky and drop-shot setups.
The one wacky senko fish I lost was because I dorked out and didn't do the above steps.
Minding the line slack has helped as well. I suspect just paying more attention to line in general has translated to better attention placed on the hookset when a fish does bite.
Thanks again to everyone for the help! While I feel like I still have lots of room for improvement, I think I've "solved" the problem.