Full Logitech support is planned for later this year. However you can use the logitech app to send shortcuts, which you can then configure in the keyboard section in BTT.
I hope you to proceed on your plan because Logitech app is crap and it is full of bugs and glitches when it comes to macOS wakeUp from the sleeping mode!
every time you need to re-open the app and start over with re assigning the buttons.