I must not have explained it correctly. I have had 2 turbo Subarus and have replaced many a pass side boot. All with OEM DP. So I know exactly what you are talking about.
This is different. Boot isn't ripped or torn. It isn't even dry. It is a fairly new boot as well. The only place that the grease is coming out is the end of the boot where it clamps. It didn't do this just before when the OEM DP was on. First spirited drive with the new DP and it was coming out the end.
To be clear, I'm not saying all Invidia DPs do this. I got mine used and I'm pretty sure the cat is dead. Which causes the cat to be hotter. Since on the invidia design (and some others) the cat is like an inch from the boot, it will cook the grease and liquefy it and it leaks out around the clamp. At least this is what I have read online (other folks with this issue) and it explains my experience.
BTW love your tuning threads, they are helping me a lot!