worldclubber, thanks just so much for this.
It's really generous of you to post. It's also good to know that my lounge-hopping plan seems doable.
Couldn't agree more about the apron views from the MLL -- a nice start to a trip. (Fortunately, I will likely already be in FRA (landside) from a flight from LHR on the night before, so, will already be in Germany.)
Thanks so much, too, for the link describing the route to the FCT -- very handy indeed!
I might need that 900m walk to burn off some of the calories consumed in the MLL!
All the best
Originally Posted by
worldclubber
As described by some of the others, it is absolutely no problem to go to the MLL first and then to the FCT, as long as you can legally enter Germany/Schengen. The security check at the FCT is very painless, so that shouldn't be an issue either.
I see your point, as the MLL has great apron views, which the FCT has not, and is right next to the open air deck (which, unfortunately, is no often crowded with smokers). And since the FCL in B is not an option, your plan makes sense to me.
Most of the walk to the FCT is actually covered by the road above. Here's the guide for the walk to the FCT:
https://www.flickr.com/photos/262849...944600/detail/
My watch says it's about 900m. As long as you don't have to schlepp heavy luggage and it's not raining heavily, just what one needs between flights. 
Enjoy!