I think you worry too much, but I also know that many BITOGers share your concerns.
Personally, I don't think the location of the BPV makes much difference. In theory, a dome end BPV seems bad, but I doubt that it actually translates into bad things in the real world.
I would worry more about the cost/benefit ratio of the M1 filter, more than the location of the BPV. I am a former M1 filter user, but have switched to Purolator Pure One filters. The cost of the M1 filters was just too high for me, & my oil changes come around every 3 months, which amounts to 6k miles.
That's my $.02
Personally, I don't think the location of the BPV makes much difference. In theory, a dome end BPV seems bad, but I doubt that it actually translates into bad things in the real world.
I would worry more about the cost/benefit ratio of the M1 filter, more than the location of the BPV. I am a former M1 filter user, but have switched to Purolator Pure One filters. The cost of the M1 filters was just too high for me, & my oil changes come around every 3 months, which amounts to 6k miles.
That's my $.02