I see tons of posts about battery-powered rigs here. Has anyone tried using an automotive amplifier? This one looks cool: NVX MVPA4 Micro-V 400W RMS 4-Channel Car Amp with Small Footprint It seems like a pedal preamp, car amp and small USB battery pack with a 12V step up cable would make for a decent portable rig that would fit on a nano pedalboard. Pair with a small cab and it could be a great little setup. Any reason this isn't more common?