How do you work out any inter-agency differences in gas planning? You discuss them in advance. My understanding is that even agencies that teach best-mix don't say you *have* to use the best mix, so you should be ok on the standard gases. I'm not Tech trained, but for a Fundies-level dive (<30m, no deco ceiling), you use 32% nitrox and do 30 second stops every 10' from 50% of your max depth. If your agency says you have to do a 3 minute stop at 15', I'd be happy to do that with you as well. I would want to use appropriate gas management (all available, 1/2s, or 1/3s depending on the situation). All-in-all, there's nothing that would stop us from diving together. You may get a little less bottom time because I would want to reserve more gas than you generally do (or maybe not), but I was paranoid about gas reserves before I took Fundies as well.
I was referring specifically to deco dives and tech configuration, but my second question might also fit standard recreational dives. All I read talks about philosophy and holistic systems and I just don't get how that meshes.