You can have mixed tech in Conquest, storyline solo, or D3 campaigns, but NOT in GSA/skirmish games, as far as I can guess based on what Dave Ferrell has said in the past.
So, you'll be able to mix tech for campaigns, but no more cloaking Defiants on GSA.
As far as the mod tutorial goes, the steps are the same. You just need to find the right .gf file setting to change for campaigns.