What you’re describing, Vince, could look like the top two lines here…
…cos a Filter will stop the unwanted notes getting thro so you need a second line to deal with them.
The 4th line shows it being done in one go by using a pipe called Transform.
An incredibly powerful tool, here it’s being used to change some notes to Ch2 & others to Ch3, assuming they’re both going out the same port.
Yep, 255 pipe limit,
but unlikely to be 50 splits/layers cos remember the above is “fixed” to route/switch things in realtime is going to involve some mappings.
I wouldn’t be able to guess the scope of one preset without knowing more about your set up.
Take a scan through this tutorial which takes the user through building up a split keyboard routing preset. It’s designed to be hands-on (and the last in a series!) but it might bring out your inner geek 
Yes, You set up which port and channel to listen for PCs in the Settings menu when the box is attached.