Hi Bill,I agree that building these contraptions will be technically challenging and never be as ergonomic as the factory designed solutions offered by Wersi.
Dual manuals with a pedal board is a must have feature for serious organ players.
I looked up the Wersi OAX1
Add-on keyboard with 76 keys that retails for $1,260.
https://www.musicstore.com/en_US/USD/Wer...-KEY0004648-000I see that Wersi has a
17-key Bass Pedal for the OAX1 that retails of $509.
https://www.musicstore.com/en_US/USD/Wersi-SONIC-OAX1-17-Keys-Bass-Pedal/art-KEY0003205-000I like the fact that all Yamaha Styles can be used on the Wersi OAX1 with Wersi designed voices.
Since the Wersi supports loading of VST Instruments, you have a limitless library of 3rd party voices to explore and enjoy.
The Wersi OAX1 is basically a powerful PC with a keyboard interface that can be updated with the latest operating system with each new OS release to access all the new features.
I enjoyed listening to the 11 new OAX Demo Songs by
Brett Wales.
https://www.wersi.net/en/en-sound-demos/Brett is a talented organist, one of a kind.