My searches seemed to mostly turn up questions about using the same controller on multiple MIDI tracks, but this situation is the reverse of that.
Example: I have a MIDI keyboard set up as one input, and a KORG NanoPad2 set up as a second input. I recently wanted to route them both to the same MIDI track and instrument. Many other DAWs have input options such as "omni", "all connected devices", etc., but not Waveform.
After much searching and exploring I finally found the answer at the bottom of the track input dialogue. The "number of inputs on this track" selection will allow you to select from 1-4 inputs per track. Works great! That opens up extra input slots in the track. Now I can assign multiple MIDI inputs to the same instrument! Nice!
