I use multiple keyboards when at all possible. I love to use my C-1 with a synth on top and a digital piano on my right hand.
When I uase the B-3, I use a suitcase on my right hand and either an old Korg Micro or a DX-7 on the top....complete "old school".
Even on my arranger jobs now, I use a controller and old Yamaha tone generator over
an old MS-60.
When I start to use my SD-5, I'll have the GW-7 on my right hand and my Hammond Melodica resting on the top.
Haven't figured out what I'm going to do with the Midjay, but may use it with bass pedals and a double neck guitar. Always have two jobs Friday and Saturday, and use different set-ups for each.
Hard to change old ways,
Russ