No need to increase amperage as LGB motors draw about 1A when starting.
I want a cheap solutions for now,dont need loconet on the Booster. Indeed the Power 8 can vary output by changing input voltage, but would need to split the track in a seconde circuit.
The Marklin-LGB locos have a label on their shell : 24V
Edit: when using the Power 8 disconnect the Centrale Station from the rails and the DCC commands are transfered to the Power 8 via Loconet?