I also don't feel that in the air is the best place to teach. Can I teach somone to pass a private MEL in 6 hours? Probably, but I won't. We just had a 310 crash nearby killing 5 people on board. We'll wait for the final NTSB report, but the whispers I hear is that the PIC was over his head with this airplane. Probably had a quick MEL transition.
For my students:
1. They get PCATD time first. I am not going to waste their time in a 310 finding out that their version of "able to shoot an ILS to minimums" and mine are different. I tell them ahead of time that they should be able to shoot an ILS to minimums in a HP complex airplane on a consistent basis prior to the course. If they need the HP/Complex endorsement we need to budget more time.
2. Same with engine cuts. Prior to engine failures in the airplane they must be able to do it quickly and accurately in the PCATD.
3. We do a night flight as part of their training. Not required, but they get it. I don't want their first night flight in a twin to be without a CFI.
4. In addition to being able to shoot a single engine ILS to minimums they will shoot a single engine VOR/DME approach. Yeah, in a real situation they should try to find an ILS, but that is not always an option around here within single engine fuel range. Also most twins have SE service ceilings below the MEAs around here. If an engine dies they are probably diverting to the nearest airport, ILS or no ILS. I don't want their first SE VOR approach to be on their own with kids on board. I also try to put them into some bad situations with difficult approaches in the PCATD.
5. They will have a flight at maximum gross weight with sand bags on board.
My goal is not to get someone through their check ride. My goal is to never hear of someone in an NTSB report. They day they walk out the door they can purchase a twin and get themselves (and their pax), in a really bad situation.