Apologies in advance for a plethora of questions ...

I've got a trip coming in the next week with the outbound journey as PEK-LHR(BA)/LHR-MAD(BA)/MAD-GRX(IB), all on one ticket/PNR (75 minutes transfer time at LHR, and 115 minutes at MAD).

As background, this is an Avios/GUF2/joker booking where it took four attempts before the IB leg finally "stuck" in the booking (thanks to BA6501 who noted that this would require an agent both to add the correct keyword and to re-issue the ticket to prevent the IB leg being auto-cancelled).

Given the trouble this booking caused, and as there are still some odd issues* I just want to check my options for checking-in for the IB flight and getting a boarding pass.

(* I can't open this booking using MMB as it just gives an error message, but when I call, BAEC say it looks good; the ticket number is there in MyFlights - but the listed route under the e-ticket number is incorrect; the IB website shows all the flights correctly, but the IB app shows the wrong booking class for the MAD-GRX leg...)

Q1. Am I correct in assuming that I should be able to get a boarding pass issued at the BA check-in desk in Beijing for all three legs? (I'll try also using the app - but as a related question as I've never done this before - the booking is for two people, so can one person download boarding passes for both people using the BA or IB apps?)

Q2. If there is some problem checking in for the IB leg, what is the best place at LHR to get this sorted? I'll have the LHR-MAD boarding passes so is it best to go to the lounge to ask about this rather than the rebooking desks?

Q3. In the worst case that I arrive in MAD (T4S) without being able to sort this out, where is the nearest connections desk?

I am sure I am being paranoid here and over-thinking things. But with the previous ticket issue problems, and the fact that the return flight is totally rammed (only non-zero availability showing as F1 J2 at the moment) I want to make sure that I know what to do in case of problems ...


(Mobility assistance question)
A somewhat separate question regarding mobility assistance for this trip. I'm currently nursing a grade 2 ankle sprain and although I can walk around, I can only do so s-l-o-w-l-y at the moment. I am happy to get myself through LHR as I know my way around, but am tempted to ask for some assistance for the MAD-GRX transfer (not least as I read that a T4S to T4 transfer can involve a very long walk).

Q4. Given this is a BA Avios booking, and I'll be arriving on BA then transferring to IB, is it possible to arrange this by calling BA(EC) and just asking for help with the MAD-GRX transfer - or it is better to do this by calling IB directly (again asking for assistance only for the MAD-GRX transer)?