I use a TD-15 module, with a custom DIY a2e conversion that I built after I lost my vision. IT's my 2nd A2E kit, and it's not that hard to do, really. The trick though is getting the pad settings right for them, and that may require sighted assistance, however, if you buy a prefabricated kit, like a complete Roland TD-Whatever kit complete with pads, then you can simply plug and play into the VST.
I use a TD-15 for it's simplicity, since it has what are called VEX packs on it, which are professionally modeled kits that use the onboard sounds to simulate drummers, drumkits, etc etc. I am currently selling my setup and going to a TD-30.
I know very little on how this whole thing works, I just know the programmer that is helping me does somethign with mouse moving emulation with keyboard shortcuts, and commands. Then he does something that uses visual text and has the screen reader read it to me with OCR somehow, but not like you'd normally use it. However, it's application specific, largely because there are multiple applications within this one we're creating. all for SOnar and some will be standalone.
Once we get this working like we can for this application and at least making it universally standalone, then we're actually going to do another version intercepting trhe framework with an actual script. As of right now, the installer, it'sself is not accessible at all. This plugin setup is working with NVDA. I don't have Reaper, never liked it every time I tried it with vision, so I don't know what it's capible of or anything. IF I can get Reaper, I can definitely make a test trial of it and make it work with Reaper as well.
The only reason I went with Sonar X3, is because it's the software DAW I was using long before I lost my vision, and after having lost my vision, I didn't want to spend the money for Jaws, Caketalking, and then downgrade my PC and Sonar, so I came up with this solution that I have created to work with Sonar and it works with virtually all versions of Sonar and is more flexible than Caketalking in some aspects, but not so much in others. In my video tutorial series, you'll see that I have implemented some custom features like precision parameter control, plugin control custom mapping and quick access, and the best part is the itegrated help function which will make anyone's work flow much easier.
Basically, my Sonar setup (which is free to use for anyone with SOnar X3 or Platinum) is one of the only DAW setups that allow you to use a physical control surface and still get speech feedback.
The X-Touch Compact I use has 9 faders, 16 encoders ad a ton of buttons, all mapped out to do what they are intended and definitely make the work flow much easier to deal with. As mentioned, see my other thread about it.
Anyways back on track. This setup for AD2 is still in beta, we have a few bugs to work out. We're also tossing around the idea of making the interface accessible with a gamepad, but we have no idea how that will turn out, but the proof of concept has been conceived. That's what I did to initially control Sonar before I got my X-Touch Compact.
AD2 comes packaged with Sonar Platinum and I'm not sure what other editions, but I do know that they are including it with some of their packages.