Dirtyswiff

So I'm sure most people who see this thread know my current situation about smog, as I'm going through threads reading about the rp supercat, I am beginning to believe this can be my alternative to oem as a TEST only catalyst. From what I read people have passed the California test and the failure rate varies but is nowhere near oem of course. However people who report it failing around as early as 4,000 to as much 12,000 lead me to believe this is not a cat designed for long term daily driving. So my question is how much success will I have just buying this cat for the test only? I figured u put it on for a day for the test and u put at the most 10 miles on it driving around and then take it off, even if it fails as early as 4,000 Miles I will still be able to use it for multiple tests. If anyone is already doing this how many smogs have u passed already? I'm gonna buy it today if I get a good feedback. Arguments and opinions appreciated, thanks.