basically, it seems like it would behave very much like a MotoGadget m-unit, perhaps minus some programmability.
Consider that device your "fuse" box. Nothing more. It appears to have internal relays for indicators, so thats good. But you will use it navigate the signal wires (control switches at handlebars) into the device, pass through a separate circuit (fuse protected individually) and then deliver 12v power to the component (light, turn signal, tail light, etc...).
Outside of this, there is a Starter Solenoid (this gets a signal from the START button on the handlebar) which "excites" the starter motor. VROOM! Once the engine is running, the stator (kind of like an alternator) creates AC current. This gets delivered to the Rectifier (stock) and to the Regulator (stock) which team up together to "recharge" the battery while your bike is running (our bikes don't create enough charge until above 2500RPMS, so until then, you're running off the battery only) and restore the depleted battery.
The modern Reg/Rec combines both functions into a single device. Rectify the AC current to DC (battery is DC) and Regulate (limit the stator from sending too much voltage to battery). Not that hard really.
The coils generate the spark basically. They need 12v power (stock BLACK/WHT wire) when the key is ON and bike is in RUN. The timing plate under the right side cover, tells the coils
when to send the spark to the plugs.
So, now you're a motorcycle electrician
Some of this is a bit simplified and not 100% technically verbatim, but you get the gist of it all now.
I honestly don't know the benefit of that device versus a regular ATC blade fuse module. Maybe some internal relays for the turn signals? I do know the MotoGadget stuff quite well. It too is pricey, but it does have some very cool features, if you're into that sort of thing. (I am, I confess). I don't think it would be hard to create a capable diagram for either route, but both will likely require some modification, mounting, and I think you'd be well served if you do use it, to go ahead and buy a modern Reg/Rec. My opinion.
Let me know if I can help-