Thanks for the replies. Putting the VST on the input FX chain is a good idea and it worked. However, I found a solution that I think works even better. Here's how I do it.
You have three tracks: 'lo' notes VSTi, 'hi' notes VSTi and 'split', the splitter. On 'split' is the
PIZ MidiKeySplit VST, which sends the notes on the left side of the keyboard to midi channel 2 and the right side to midi channel 3. I set my MIDI keyboard to output MIDI on channel 1 and 'split' to input MIDI on channel 1.
'split' then sends MIDI to 'lo', from channel 2 out to all channels in, and also sends MIDI to 'hi', from channel 3 out to all channels in.
The record-arm settings for 'lo' are to accept input from MIDI channel 2, 'hi' from midi channel 3. Also, for both 'hi' and 'lo', set record
utput(MIDI).
For 'split', set record:disable(input monitoring only). Now, record-arm all three tracks. When you record, Low notes, and only low notes, will record into 'lo', and only high notes will record into 'hi'.
You can save these three tracks as a track template and use them quickly, whenever you want to split your keyboard. Just drop in the template and drag 'lo' and 'hi' under whatever VSTis you want to use, so that the VSTi track is a track folder and 'hi' or 'lo' are sub-tracks of the folder.
One thing that would be nice is if there was a VST midi splitter that learned/listened for the note you want to split. I know there's a JS note range filter that will listen for high and low, but I haven't found one where you push a button on the GUI, then hit your note, and now this is the note where the split happens. If anyone knows of such a thing, I'd like to know about it.