Mainfrog 2 you've just proved my point perfectly .
To transmit to atc tower you just need to key the mic on the ctl coloumn already in your hand . You will already be calling mayday anyway as it is mandatory in BA .
To contact the cabin crew you need to select cabin interphone on the centre pedestal ie look down away from the shop then press the cabin call on the overhead panel yes more distraction then wait for a reply from someone who has to peer through a
very small aperture unless they leave their seat and you suggest this should be done with 100 seconds to touchdown . The last time a BA 757 was trailling significant amounts of smoke ... you know the one the went into GVA , nothing could be seen from the cabin.
No matter what the response from the cabin you would still execute the engine fire checklist .
You missed the point if you think that I do not believe in involving the cabin crew . So to reitterate I'm suggesting that one pilot will fly the plane coping with assymetric flight on short finals probably transmitting to atc whilst the other pilot executes the emergency checklist .
Once the a/c has touched down one would expect a cabin crew member to use the alert call to advise the flight crew of any untoward signs . Now that would be CRM in action .