I am sure you know this and it’s trivial for you, but at one of my previous clubs an instructor use to make people kit up and go in the shallow end of the pool first.I know this is a SB truism but there is a reason why it's better to let (some) people kneel early. When the student has below average talent, it's too much task load early on and is aksing too much in the pool. That can cause them to get frustrated and do worse. Especially when they are in a group of 3 or 4 people and they see that other people are doing much better. Letting them do stuff like the mask off skill kneeling in the pool and OW 1 lets them learn in smaller steps. Once they feel they're doing ok with the skills you can let them hoover or be on their fin tips in OW 3 and 4 for the skills. The OW class is not for the instructors ego but for the student to learn basic skills in small steps. OWD cert is a licence to learn.
If you have a good students, you can let them hoover in the pool, but it would be much sense to make it a rule.
In there, you would naturally move in horizontal trim since it’s shallow.
He would do the weight check for them and once they got more confident he would make them swim around in the deeper part of the pool.
Aside from people with phobias and other issues, pretty much every try dive ended up with people swimming in trim and looking quite comfortable in water.
I don’t have your experience so I trust you that some people may need to be taught in knee to overcome some issues, but then it would be the exception.
I like to think that when people criticise people teaching on knees they are not criticising that exception but talking about the fact that a few shops will take 4 people set them on knees and try to get them through all skills as quickly as possible.