CharlesiNsti
Sweet, thanks for the info. A lot of learning how to use Mobius involves searching the forum for examples, and crosschecking the old 2.0 Documentation (which gives you a full list of all the functions) with the official 3.0 documentation. 3.0 introduced a new scripting language (MSL, whereas 2.0 has MOS), which isn't fully mapped out yet in the documentation, but if you're good with context clues you'll be able to pick up on it through forum examples. Between those three resources and trial-and-error with your own setup, you should be able to find a flow that suits your needs. It really helps to explore!
So, working on build 47 as a plugin, here's an example for an MSL script for a record/play/overdub button.
#name record/play/overdub
if mode == :reset Record
if mode == :record Play
if mode == :Play Overdub
if mode == :Overdub Play
1) Right click Mob UI > scripts > editor > paste this script (right click to paste), then save. You can hit "Run" in the editor too if you want to test it in action before trying with a controller.
2) Assuming you already have your MIDI device set up to send messages to Mobius via Reaper, right click Mob UI > Bindings > Manage > Right click Binding Set > Add new (name it whatever).
3) Find the record/play/overdub script in the second column and drag it over to the right column. It brings up a window where you can assign it to whatever pad or button you want to use on your controller. As a shortcut, you can use "Capture" and press the trigger to assign it.
4) Exit Bindings, right click Mob UI, then under "Binding Overlays" make sure whatever you named the Set has a check mark by it.
5) Now, when you press that trigger on any track, it will run that script and emulate the Boss RC-300.
6) (optional) set your tracks up to sync to each other how you'd like based on syncronization settings.
That's essentially how to do the trigger.
As for changing from part A to part B, there are several approaches you can try. I'd look into what is called Loop Switching and read up from there. There's a possibility you run into a minor bug in b47 while doing this, which I've reported, so hopefully it'll be fixed soon.
At any rate, please Share Your Content when you get it up and running and make something cool!