I’d suggest maybe a Roland BK7-m module and an ultra lightweight controller. You might get away with a 48 key if you don’t tend to whizz around on a 61 or 76 much…

BK7m’s are not as rare as BK9’s on the used market, and a controller gives you a lot of choice how you map buttons and sliders so your main functions are easy to get to on the keyboard.

What’s the weight of your current rig, Deane? I’m pushing 70 (okay, 69!) and my 20lbs BK9 is still easily moved despite being a 76!