Hello!
I take it your using your EFB for items other than charting? (FCOM's/Perf etc.?) -
Charting, company documents (Operating manuals and suchlikes), briefing packages (fully paperless apart from the flight log and w&b). Airplane documents, checklists, performance not yet because no certified (at least not by our authority) versions are available.
...with regard to EMI and HMI considerations, did you get an outside agency for EMI tests?
EMI was actually measured inside the aircraft by a certified avionics maintenance company. No test flight was necessary, it could be done on the ground.