I don't think it would help much, tbh. You still have the main problem of why Japan would build tanks in any decent number. The tanks they had were more than sufficient in China, as the Chinese didn't have tanks or anti-tank guns in any real number, and they assumed that any fighting against the US, UK, France, and Netherlands would either be fighting against colonial troops without much tanks, or on islands where tanks are less useful anyway. Even if they thought they needed tanks, say, for a showdown against the Soviets, you still have the issue that even if they build competitive designs, they can't build them in truly useful numbers with the economy they have and when most of the steel they do produce will end up going to the navy anyway.
Now, if you want to do an ISoT for fun anyway, then I did once post an ASB thread in which the ASBs just give Militarist Japan one milllion free panzershreks. That wonkt win the war, obviously, but I think it could make things a bit more interesting...
Well, at some point they give the Designs to the Germans who *do* manage to make better use of them. Having 1944 tank designs built and in service by the Summer of 1941 allows Barbarossa to succeed, knocking the Soviets out of the war. This does delay the dropping of the Bomb on Japan by more than a week. (The only question is whether 1944 tanks in 1940 are enough to actually win in Africa.)