I found a quite simple way to route audio from audio in jacks through AL’s effects without any further processing and without having to press any keys using the Korg MS20-plugin that I haven’t found anywhere else so far. I use this to route an external instrument (accordion in my case) through AL and it works quite well.
Only downside is that I have to hit a key on the keyboard once the preset is selected to activate the newly selected preset. Maybe someone has an idea as how to avoid this step.
You can find an AnalogLab-preset in my Google drive: AudioThruMS20.labx - Google Drive
Enjoy,
Richard