I see that you are from Akumal, and I would like to take a moment, perhaps an off-topic moment, to suggest other ways you could work to improve OW training.
A number of years ago, PADI changed its OW class, adding a number of new requirements and putting a significant emphasis on buoyancy and trim. There was a transition period after the announcement before they had to be fully in place. During that transition period, I went to Akumal with some friends and was allowed to use a shop's resources to certify them. I fully used the new requirements, including teaching them trim. Since I knew they would be using rental BCDs, I brought bungee loops that I could use to put weights on the cam bands in order to distribute the weights for better trim. As my students were putting them on the tanks, the shop's instructors gathered around to see this strange sight. What was I doing? Why? What is the point in distributing weights like that? I explained what trim was and why it was important, and I told them they were going to have to be teaching it soon because of the new standards. "What new standards?" they asked.
Two days later, we came back from a morning dive in Akumal Bay, and the DM, who we had not seen before, came to the 3 of us and told us he noticed that we were the only ones signed up for the next dive, and he wondered if he could take us some place more fitting our experience level. We eagerly agreed. Unfortunately, we were joined by another couple, and when we got to the more advanced site with its coral canyons and swim throughs, they were not skilled enough for it, so we swam over all of the good stuff. After the dive, the DM apologized, saying the new couple only had about 25 dives and so were not skilled enough, not having the vast experience the three of us had. I pointed to my two friends and told him that I had just certified them the day before, and he had just witnessed their first 2 dives as certified OW divers. It turns out that when you teach buoyancy and trim in the OW class, people learn those skills pretty quickly.
A year ago in October, I was in Akumal again with family. I took my granddaughter out to snorkel over the reef in Akumal Bay (or what is left of it), and we passed over an OW class. They were in a circle, kneeling on the bottom, obviously overweighted as they did basic skills. There was no sign of trim weights.
So, while you are working to reform OW instruction on gas planning, you may want to branch out to other areas of instruction that could stand some improvement. Before adding new skills to the class, get your colleagues to teach the ones that are there now.
