I feel like a lot of Steve Hogg content seems logical, but the more you think about it, the more you start to see that he makes some assumptions that generously states are reflective of his own physiology and lifestyle.
I will never forget reading a long-winded thing about why midfoot cleats might be interesting--and it came down to "you walk up stairs not on your forefoot but evenly with your whole foot, which = midfoot loading. Not only does that not make sense, but I also walked stairs for like 30 minutes trying to figure out how Steve would have come to that conclusion and decided it had to be that he has never paid attention when walking a staircase barefoot and made assumptions based on how a typical sneaker (not running shoe) supports a foot, which is not the same thing as how loads are managed by the foot.
There are shades of that here too. The premise is balance, but static balance on the trainer is different than balance in motion, as moments matter. Balance when accelerating is going to be different than balance when climbing. How often are you actually going to be going at a constant speed on a straight, flat road with no wind or external forces? For what percentage of your riding is the scenario outlined in the post relevant? 1%? 2%? Balance might take effort; holding yourself up might take effort, but if the goal is less exertion for speed, I think most people will find the idea of static balance on a trainer rather irrelevant in the face of aero concerns.
IME, I can move my saddle all the way forward on my Kickr bike with no adverse effects, except for changes in muscle recruitment between my glutes and quads. There is a saddle position where I can feel my glutes work when I do intervals--to me, this is where I like to be as primarily an endurance rider thinking about yet another Unbound 200 or some equivalently long event. It's got nothing to do with balance, and it's still really far forward--I would guess it's ~4-5cm forward of where I was in 2018-2019 when I started to question this stuff. (going from 15mm setback on a 74-degree STA bike to 15mm forward on a 75-degree STA bike)
But what do I know? I am not a fitter.