hmmm this sounds kind of like the transition i made about 8 or so months ago. i used to have a slightly different grip on FH vs backhand. The forehand grip was more naturally closed...which resulted in a very spinny forehand and easy to do an inside out forehand loop (hitting the left side of the incoming ball quite easily if i wanted). the problem with having two different grips was, like you said, fractions of delays in the transition from forehand to backhand. which was really hurting my progress as many of my smarter opponents purposely target my backhand for easier points.
So my (at the time) coach had me switch to a completely neutral grip. My forehand loop kind of took an instant downgrade...... and it had a more natural hook tendency (and more open face hit) as i was trying to adjust to the new grip. but my backhand instantly became better and of course the transition from FH to backhand was noticeably improved. Not long after that, I switched to the hurricane rubber on my forehand..and wow. this rubber really is designed for a grip like this with a more open face hit. I really learned to harness the power on my forehand with this grip...and i can honestly say my forehand is better than ever (most of the improvement is coming from the increased use of my lower body...but still the grip helped).
and more importantly...my weakest stroke...my backhand...has only gotten better as the months have progressed. i'm consistently getting kill shots with my backhand in every match. not to the same extent as my forehand, but its no longer an area my opponent can target for easy points every time.
Interesting that you mentioned H3 in relation to all this, but that's very much my experience as well!
I switched to H3 on the FH about 2 months ago, short game, services, and counter-looping improved very quickly thereafter, but I wasn't quite getting the FH loop against blocks the way I wanted either in practice or in games. I think due to the harder sponge, using my old stroke I was brushing more as I wasn't hitting into the sponge as much, and when I tried to hit into the sponge a bit more, then my consistency suffers. About 2 weeks ago, at the end of a practice session, I decided to try out the more open racket then brush up method, and it worked surprisingly well. I had used that technique before when I first started learning TT, but after switching to TB ALC + T05s, that didn't work. The ball shot off the racket too quickly and it was too straight without enough curve/spin, so I haven't used it in many years.
Last week I tried adjusting my grip a bit higher up while also using the new technique, it was a disaster, in both practice and in games. In retrospect, I think the issue is that my grip was somewhere in the middle, so while playing it would sometimes slide up or down and that was the root cause of the inconsistency. During club play on Sunday, a clubmate who plays with the H3 on the FH said that he took some coaching lessons and was taught that you should hold the racket high up, with your thumb resting on the "D" in "DHS", for both FH and BH. So yesterday during practice I decided to change to that, which required me to hold the racket all the way up the handle.
Well I gotta say, it worked extremely well! There was no more guesswork with where I'm holding the racket. The new technique worked brilliantly with the H3, and FH/BH transitions were a lot smoother not to mention my BH was felt a lot more solid.
One thing I'll note with the new FH technique is that it's not so much a "new" technique, but a completion of my old technique. It's not exclusively a hit then brush up technique, but depends on where my racket starts relative to the ball and the ball's height. When my racket has to start far below the ball, like looping something from below the table or a ball that bounced higher than I expected, I would close down the racket, similarly for counter-looping. This technique addition ensures that I get the best contact possible regardless of the ball, whereas before when I tried to close down on every ball I had to often lift my elbow or get poor contact/whiff entirely.
