I recently had success reviving a weak Honda transmission. It was shifting lazily and at low rpms, flaring on 2-3 and 3-4 upshifts. Here's what I did:
a) Added about 3~4 ozs of Chemtool B-12 to trans.
b) Let my 16 year old step-son practice parallel parking it for about an hour (this really helped!)
c) Next morning it was dramatically better (alternatively, drive it a week
d) Did a drain and fill with MaxLife, drove it another week.
e) Drained/filled again with Lubegard ATF
The transmission is now excellent, no flare, shifts firmly and at much better shift points - much higher than before. Each of the three steps had a distinct impact (additive, 1st d/f with Maxlife, 2nd d/f with Lubegard). The trans. is only 6.9 qts and you get about 3 qts with each d/f, so this was a substantial fluid swap even though only two drain/fills. I'll do a third with more Lubegard in 10 or 15k miles.
IDK Honda's well but the cw is the seals in the valve body get hard and can't make adequate line pressure. My experience seems to validate that as seal conditioning would happen with each step. I can't say if that's your problem, but this sure worked for me, but it wasn't as bad as your situation.