I have a lot of kitchens to install on walls with double drywall over metal studs. My Franklin Sensors stud finder is great for single drywall but is failing on double, I have been having to search for them with a screw and things aren’t really OC. What strategies are recommended for finding studs in such a situation?
The same way we find studs for single drywall.
Magnetic stud finder
Your drywall has to be screwed in properly. You will have vertical columns of screws. When the magnet hits something, go up or down a little, if it hits a vertical column - there is your stud. Since it is double drywall there would definitely not be skipping of studs so you should be able to mark everything in kitchen in a few minutes.
Worth investigating: NEW Walabot DIY Stud Finder In-Wall Imager.
You could consider avoiding the metal studs. Use proper drywall anchors for #12 screws. Drywall is very strong if the clamping force of a fastener can be spread out.
If you are installing many kitchens, I would think you should get a professional expert to recommend the fastening system for hanging cabinets on 1 inch thick drywall on "heavy gauge" steel studs.