PPS: I played around a while ago with Jazz-Soft--a tool for using a browser with mid gear. It just dawned on me that you might be able to create a personal/customized html file to send sysex commands to midi gear if it is connected to a computer. Even if ultimately you want to have the sysex commands coming from your keyboard, it might be possible to test the sysex chains via a browser.
Not sure if I wrote about tests with Jazz-Soft here or elsewhere. At one point I was exploring the possibility of having a web-based utility that would do some of what e-loader does (and other functions--such as my syxer utility, a parameterizer for generating presets, etc. ).
I seemed to recall posting the results of tests somewhere, but no one was interested then.
MIDI Input Viewer from Dr. Steve
I see that I had buttons for remote control on and off. I also was able to obtain patterns in sysex format by requesting a song and sending acks. As I recall, I just did a hard coded pattern--no inputs for selecting pattern bank and slot. It was a test of concept kind of thing. If people want to develop this further, I'd be happy to share what I know. Unfortunately, I no longer have time and energy to devote to develop something like this the way I imagine it can be used. Also, I cannot keep up with changes in html and other www consortium things.