Your profile says you're an AFF-IE with 45 years in the sport. Where do levels 4 & 5 include docks? I've been an AFF-I since '90, and every school I've taught at 4's & 5's are about heading control and turns - docking comes later.
Anyways, to my mind, having them use a point on the horizon for heading reference during turns makes them less dependent on us and establishes practices that they'll use on their solos. (Obviously on docking dives they would use us for that reference.) Indeed, on later levels I like to stay above and behind them. (Other than for docking), I don't want them to see me. I tell them that unless I'm giving them hand signals, just ignore me and do their thing. One, this gives them the idea that they don't need us, and two, it gives me an idea how they're gonna act when we're not there.
On a side (but related) note, I always find this scenario funny: At the end of those dives I like to show up in front of them and give them a smile and a thumbs up, let them know they're doing a good job. Then I go to their side for the pull. Often they follow me. On the down side, I'm trying to get to their side so that I can watch the pull and assist if needed, and them following me makes that harder. On the UP side, that is usually their first intuitive turn. That is, they're not 'mechanically executing' a turn, they're just flying that way without thinking because that's where their attention is. It makes for a good teaching moment.