The Orba may not make a sound but your DAW will like it okay. So, without overwriting your original presets and losing them, just create a duplicate of one of them, give it a Name and Description to identify it, and map any eight MIDI notes you want in the Tuning section to make a custom Kit. It's not a Shaker so the shake gesture has no effect either. But in Logic, button 8 gives me a Tambourine, so it's sending note 54 as expected. So, what happens when I load the preset? If I turn up the Orba speaker, that button plays nothing (there's nothing defined in the internal synth setting to match it). However, there are very good reasons to have and use MIDI controllers to make your beats Stay with me and let me point the advantages of having a MIDI keyboard.

Also edited the section at the top of the file to display what I wanted to for Name and Description (this is what shows when you click the preset in the app). I changed the last note, 70 (Shaker) to 54 (Tambourine). For the test I did, I saved a copy of Orba.orbapreset as Test.orbapreset (in the same folder). The eight notes map in order to Orba buttons 1 to 8.

These are the MIDI notes the Orba will send both internally to the synth and out to the host (Reason in your case). You can ignore most of this, you're only interested in the notes (36, 38 etc). orbapreset files in the Presets/Drums folder all have a section near the end like this: Sorry if it looks complex but it really isn't. I'm slowly working through these preset files to try to understand them. I've tested this in Logic Pro X, it works.

Midi controller for reason