They can control the follow-up information that the MHRA may require or ask to be provided, and we all know that NWBO is notorious for being slow in providing it. So yeah, they can control how quickly the decision is made.
"We know they [NWBO] requested to be in the expedited process, but it does not seem as though they are.."
but it would be somewhat peculiar for NICE not to be in talks with NWBO over the likely price of DCVax-L especially when (as most unprejudiced commentators all agree) ) the MHRA are imminently likely to be giving its blessing to DCVax-L. After all, NICE and NWBO have been in talks for years so why stop now, just when when an agreed price is the last piece of the jigsaw for a treatment which is clearly needed and is the first advance in 30 years of the treatment of a near universal killer.
I doubt that NICE protocols are so inflexible that the process can only run like a commuter train stopping at every intermediate station. Instead, when the need is there the protocols must/should/could/ought to be be adjustable so that the process becomes an express train with no stopping from beginning to end.... and the need for a speedy resolution of the negotiations is definitely there.