I know BA award miles and TPs per sector flown, and according to fare code on the ticket. I also know what TPs and miles to expect if I book JNB-x as a single sector flight.

What I don't know is which cabin and fare bucket BA/Comair will book me into, and therefore what mileage and TPs will be earned for that sector, when it's part of a longhaul itinerary.

As you're probably aware, for longhaul BA lets you choose WT, WT+, CW or F (and those with various degrees of flexibility), even when that cabin is not operated on your connecting flights. On those you will then be seated in what BA considers the nearest corresponding cabin. In my experience this has been full-TP economy on AY operated HEL-LHR sectors when my onward flight is in WT+. I'm trying to ask if it works the same way with Comair.

What I'm trying to achieve with the JNB-x leg: To get to "x", obviously. The location of "x" has not been decided yet, but if it's a place BA does not fly direct, I will have to connect in JNB or CPT. I'm trying to figure the most cost-effective way of doing that, which may be either a single HEL-LHR-JNB-x return ticket, or separate HEL-LHR-JNB and JNB-x tickets, depending on the price of the day. I'm also trying factor in the TPs earned, and see if we can get someone traveling on this booking to Silver while we are there, so as not to lose the inbound TPs in the membership year reset.

Ok?