At 23 minutes of this video. SSI SA Dr. Heidi Fearn explains how just scaling power and size causes problems. (heat, arcing and other problems).
For Mach effect propellentless propulsion it will be better to go to an array of smaller devices.
They expect 1-5 years to get to 1-5 millinewtons of thrust. (Using better materials and other near term design improvement.
Tajmar has replicated the 2 micronewton level and will scale to 12 micronewtons with a larger set of discs.
In 5-10 years, have array of several devices to get to 10-20 millinewtons.
10-20 years, increase thrust to 1 newton for each device.
Test arrays of 100 – 1 newton devices
MEGA space propulsion would be 1000+ 1 newtons devices.
MEGA would be powered by a 5 MW nuclear power source.