they aren't going to open those doors and kill their big panel business.
It won't kill the Big Panel Business.
The big panel business is exclusively for Linux. The market for a $30k seat running Linux has virtually no overlap with the market that will buy a $1k seat of Mac/Windows and a $4k Control panel. Implementing an SDK/API will not convince anyone who needs Linux to buy Mac or Windows instead. The $30k customers are big iron shops with a Linux workflow. The $30k Big Panel in a Big Room is part of their value-add.
Moving to an SDK/API will allow BMD to get out of the business of fixing third party control panels. All they have to do is support a single API per platform, and the control function becomes the responsibility of third parties.
it's a lot harder to change the controls in daVinci Resolve than people understand, because some of it is hard coded into the current software
IMHO, they should bite the engineering bullet, and not change the controls, but overhaul the entire control system. They should set it up so that every control is connected to the API as part of the same process of connecting it to the UI. Whenever a new control, or a new parameter is added, the API is updated immediately as a matter of course. This investment of time and money would let users have any kind fo controller they wanted. It would also allow developers to create new products that would stimulate the DaVinci market.
Imagine, for example, a developer making software that allows you to use a Kinect to control resolve with gestures in 3d-space. Or is someone adapted one of those large AP touch screens into a control surface?
It could really make Resolve stand apart from all the other color grading solutions.
So, first we want the software for free (or peanuts) then the hooks for 3rd party panels for free
I think the API should be confined to the paid version. I'd even pay a few hundred dollars to upgrade to that version, provided that the API worked, and was completely comprehensive. I think other users would be agreeable, if the final version was something to write home about.