I've never seen a defouler or simulator actually work. I've seen a few that work for a couple of hundred miles or work time to time, but nothing that's consistent. The best bet is to go with a high-flow catless like @KGI2019 mentioned.
Some of the high flow cats (AA, AMS, MAPerformance) flow...
MHD/BM3 is a shitty tuning experience for the tuner, where Ecutek is a "shitty" (though it's actually amazing) experience for the driver. The gen2 B58 obviously is lacking some features that MHD has, but they'll come eventually. You tuner will be able to deliver a much better tune using Ecutek...
The cheaper solution might make sense for you if it holds but if it doesn't, you're going to pay for both.
1. is going to be a rough solution. It'll probably live life as a daily for a while, it should also absolutely be disclosed when it comes time to sell it. The scoring on the cylinder wall...
Mike texted me back the other night, but I forgot to update. He (EOS Shop Car, neon green if you watched the TX2K vids) doesn't run a return line on his setups, though he doesn't run Visconti's stuff, it's custom.
I totally agree on the fit and finish portions. I'm the same way, I want all my...