The BA 2 x 32kg only applies to BA flights only as stated on https://www.britishairways.com/en-gb...age-allowances

For MH, the only benefits will be that as specified for OW benefitsAs a Sapphire frequent flyer, the following special checked baggage privileges will apply when you fly on oneworld airlines:

• On international or domestic itineraries using the baggage allowance "weight" system - 15 kgs in addition to the ticketed Economy Class baggage allowance.
  
• On international itineraries, that include domestic sectors, using the baggage allowance “piece” system – one additional bag*, weighing up to 23kgs, up to a maximum of two pieces.
  
• On purely domestic itineraries, using the baggage allowance "piece" system, for tickets with no ticketed baggage entitlement - the assurance of one piece of checked baggage, weighing up to 23 kgs.
  

So would seem thatr the allowance will be linmited to 1 x 23kg