I'm trying to extract the best routing possible out of the ~£2.4k ex-UK F fares that are available to selected West Coast cities (LAS, SJC, PDX) from August.

Ideally I'd like to route via the usual LHR JFK LAX, but I'm struggling to find the results I want. I can get routes via LHR LAX at that price (indeed that's one of the defeault options that shows up on Google Flights), but as soon as I add in LHR JFK LAX it just comes up with £12k fares.

ExpertFlyer doesn't seem to list the fare basis code in question (ALX8T1S4) but it does show the MPM as being the same across all other fares, which is approx 6300-6600 for most (non-London) UK origins to SJC. It also shows that there's a deduction of 550 miles for flying via NYC, DFW, CHI etc. Obviously the MPM may be different for ALX8T1S4, but if so, I don't know what it is. Either way, I can't imagine that LHR LAX JFK is foul of it.

LHR LAX JFK route seems to comply with category 4 - flight restrictions (it'd all be BA/AA flights) and category 9 - transfer restrictions says:
Which, in my reading, suggests that I'm fine to have two transfers in the US (even though I would be changing between BA and AA numbered flights at JFK or LAX). Or does
Actually mean that you can only transfer between AA and AA flights, or BA and BA flights, but not BA to AA or vice versa?

Am I missing something obvious here?

I guess to an extent it's all rather nugatory seeing as there are still options that will get me 1500 TP for Gold (with the BAH offer, e.g. LAS via PHL as I've mentioned previously). But if I'm going to trade some flight-time in F for an extra flight in J to earn extra TPs, I'd ideally like it to be in a "proper" business cabin, not armchairs or 3 by 3!

Does anyone else have any other ideas for how to make this fare reach 1500 TP with "proper" J for most of the bit that isn't F?

Thanks.