Just wanted to give an update:
I've been using the setup described in the OP for over 3 weeks now as my regular racquet. The first few days, as I noted, I had issues with the swingweight being too close to my threshold. But since then, the racquet has felt lighter and lighter every day. My arm seems to have made the adjustment, and I haven't looked back (with the exception that I flirted with a 16.3-oz setup too, but decided to put that aside until after the summer tournament season due to the high swingweight).
Now that my arm is accustomed to the swingweight, I have a lot of versatility on my serve again. Not only can I use my heavy hard kicker (my bread and butter serve) but my twistserve seems to get more effective with this setup each day, as it seems like my racquet head speed is increasing steadily.
The same thing is happening on my groundstrokes as what I described on the serve. As my racquet head speed increases, the setup seems to become better for hitting spinny Federer-like precise dippers. But I can still unload on a flat ball fairly well (but not as well as my 16-oz setup).
My defensive ground game is very strong due to the spinniness. And having the added weight in the hoop makes it a solid and stable return racquet. My ability to change direction on the return by, for example, hitting a topspin 2hb lob return off a 2nd serve, is much improved by having so much weight in the hoop.
The best part of this setup is still the fact that my confidence in my serve-and-volley game is as high as ever. The recoil weight of 177+ makes the volleys incredibly stable, making those all-important precision knee-high first volleys routine. In singles, my favorite strategy is to serve and volley behind Rafter/Edberg type heavy serves that give me time to always take the first volley in the air. If I can hit the first volley before it bounces, I can always seems to direct the ball accurately to the right spot, something that I struggle with when I use any normal stock racquet.
I'm still sticking with the 67-lbs Kevlar hybrid stringing setup, but I may experiment with dropping the tension down a pound or two to see if I can add a little extra pop on the serve without sacrificing too much depth control on groundies.