Emu XL-7 & MP-7 User's Group

Hey heres a seemingly stoopid question. As usual I am only posting 
because I cant find the answer anywhere. 
In a year of using my MP-7 I have yet to use any tracks on the B 
channel. Yeah well I have other grooveboxes and samplers going too so 
I havent need it. However I just got an EMUE5000 and my plan was to 
have all the Channel B tracks dedicated to it. So I noticed some 
strange things about the tracks 1B-16B. Let me get this straight.

1. The Mp-7 can only accept 16 incoming MIDI channels
2. The only way to play tracks 1B-16B with an external controller is 
to set MIDI channel in to B in the MIDI menu thereby making it 
impossible to play tracks 1A-16A....If my EMUE5000 is set up for 
tracks 1B-16B (output B) the only way to control it live is to go 
through the MIDI menu and change the MIDI in channel. Kinda 
inconvenient dont you think?

So heres my question, I set MIDI off for the MP-7 for tracks 1B-16B 
cause I dont want the sampler and MP-7 playing at the same time. I 
set MIDI merge to B on. I set all B tracks in the Pattern menu to ext.
However, the sampler does NOT play unless I turn on track 
rechannelize to on, this is bad because I prefer to be able to change 
channels through my controller and be selecting patches on the MP-7 
while I play on a different channel with the keyboard. 

Does the fact that track rechannelize must be on for it to work 
indicate that my controller is outputting the wrong channel. Unlikely 
cause it only outputs 16 MIDI channels.

Thanks in advance and sorry for the long post.