I find that I want more live, quick control over things like volumes, reverb amounts and such. I’m wondering if anyone has succinct knowledge about using midi to control more than one or two things.

I’m looking at the Korg Nano Controller or something similar. As an oldie I may be partial to a midi in/out unit unless you can show me how to use usb without adding much more equipment. Warning, I know little to nothing about midi control signals.

What is it that you want to control?

I have two goals. First I want to have more control over my s975. Secondly I want to pair a Privia 360 with a Korg MicroArranger.

I would say that before you get a controller you need to be sure that you can actually use midi to control the things you want to control.

admittedly I don't actually know how much of the psr or microarranger can be remotely controlled. once you know that you can choose a controller. Maybe use a computer to fire midi commands at the keyboard to find out what works?

I have a Yamaha MU80 which has a lot of real time control available via XG parameters, but i have yet to find a stand alone controller that can actually embed a variable controller value into an XG parameter that it could send down a midi cable.

Nevertheless you can certainly control some reverd, effect, volume and filter settings using standard midi controllers, so if that's all you need then you should be in with a chance.

You may have to use a midi hub to connect the nano controller to the keyboard, I don't thing you can connect them directly.

As John mentioned, you should start with the midi implementation of each gear in terms of what can be controlled from an external MIDI device. The Korg NanoKontrol2 you mentioned is really for working with DAWs or a software arranger like vArranger. If you just want to control volume and reverb, you could use something like ControlFreak by Kenton if you can find a used one. The Korg MicroArranger has a very good MIDI implementation; many of its functions can be controlled by standard MIDI messages.