But the real issue here isn't so much gas planning as it is communication ... and that's something that you need to establish prior to the dive, in order to avoid confusion and stress on the part of those you're diving with.
Only a few weeks ago I was in a similar situation to the OP of this thread. I had had a very bad year of diving, with a bad injury keeping me completely out of the water for several months. I planned a dive trip for soon after the doctor told me I should be sufficiently recovered, and that trip included two days of deep technical diving. Because there was a question (due to the nature of my injuries) as to whether I would be able to perform certain technical skills well (like a valve shut down), the dive operator and I agreed that it would be a good idea for me to do a day of pure recreational diving while wearing technical gear and practicing those skills in the open water.
So I did a two tank recreational dive in Cozumel, with the legally required DM and a couple of other divers. The DM was told what I was doing and why. The DM and the rest of the team were in normal AL 80s. I had double (back mount) steel LP 85s overfilled to 3200 PSI and an AL 80 carried as a deco bottle--meaning I had more gas than the rest of the group, including the DM, combined. In the dive briefing, the DM explained his elaborate system for communicating PSI remaining. I listened as I always do, but I assumed that that part of the briefing did not pertain to me. As the first dive progressed, I practiced gas switching a few times, so I was breathing off of each of the three tanks for a while. When we were pretty well into the dive, the DM pointed to one of the other divers and signaled for PSI. The diver responded. He did the same with the second diver, and the diver responded. When he turned to me and gave me the same signal, I at first looked at him with a "You've got to be kidding me look," but he repeated the signal, somewhat insistently. I then responded by pointing to my doubles and giving the PSI and then pointing to the deco bottle and giving the PSI, indicating I was now down to about the same amount of gas the three of them had started the dive with. As we got closer to the expected end of the dive and the other divers were approaching ascent time, he did the same thing with everyone, including me.
Just following required protocols, I figured.
Back on the boat during the surface interval, I didn't say anything to him about it--his rules, I figured. The other divers, though, had a good laugh about it talking with me. It had not occurred to them how much gas I was carrying. It was a good chance to talk with them abut the differences in tank volumes between the LP 85s and the AL 80s, etc. The DM was not too far away, and he must have been listening, because on the second dive he not only never asked me for my gas amounts, he even let me stay down longer after the others had gone to the surface.
I agree, then, that communication of what is important is the key. In my case, a simple solution would have been for me to indicate that I had checked my pressures lately and found nothing unexpected by merely returning an OK signal rather than go through the elaborate procedure he required of the others.