If they wanted to make a module like that, I guess they would.

There are solutions, from a folding screen like technics kn7000 or like a laptop, to a 20x108x2 cm "break out" box containing the necessary aranger buttons (intro, vars, ending, OTS etc.) that you can put virtually everywhere, connected to the main unit or rack unit with a simple cable.

But usually, users' wishes and marketing plans do not mix well, especially in large enterprises. Marketing wants to be able to sell with the highest margin, and R&D for a new product is absorbing funds like a sponge. So, better in the long term to feed the public with evolutionary and not revolutionary ones. Then, after years of thirst, even muddy waters can taste like Evian.

What's holding Yamah or any manufacturer from producing something that users wish?
they have 76 keys mechanism, the sounds are already there, the memory cost is low, the OS is going to be "transferred" to the new keyboard and some things would be tweaked, marketing costs will be the same.

If you buy such a thing , and it does the job, you probably won't change in the years to come.

Fran Carango comes to mind, I don't know him personally, or have collaborated or anything, but I think I remember posts of his praising the Roland G1000 which is old enough. There are probably better boards out there, with better sounds and better this and better that, but this keyboard probably does the job well and that's why he keeps it? Others may do the same.

Bottom line, if it seems like it won't bring profit, companies will not do anything in a million years. We can dream all we want.

Sorry about the rant, back to work now.