From: St.Petersburg, Russia
John and I haven't gone any further than to discuss the possibility "in general." We haven't done anything like discuss house rules or settings. I'm inclined to tell him all settings in favor of Japan (PDU On, Realistic R&D Off, etc.) with one concession to the Allies: historical torps off. I don't think this gives the Allies a huge advantage, at least the way I use subs, but it helps when you know the subs aren't entirely useless early in the war.
PDU ON, Realistic R&D OFF in exchange for good torps early on? I think that might be relatively balanced, but the balance will come from mutually breaking an aspect of the game in half. Good torps in 1942-43, when Japanese ASW is extremely weak is huge. So is ability to field A7M3s and similar on about 1/44.
Just in case, I'm personally more in favor of setting a HR limit on plane acceleration instead. It is annoying for me as a Japanese player, but otherwise there is just too much temptation (and ability) to accelerate key planes ridiculously.