Should I muck my horses stall at farm where I board?

I board at an old horseman farm; economy has really hurt them, the place has seen better days. Steve and Susan are very experienced, worth their weight X 10 in gold for the loving care they give the horses, best hay, notice every horse, if it gets a boo boo, you need help they are there, 24/7 on site management, medical care when the vets not available (he has antibotics bute etc and knows what to do), calls my horses in from field when I want to ride (she loves him) Steve was a jockey when young, learned the old horseman way; hard work and under many old timers that knew their stuff. His wife Susan has been in the business her whole life and seem to know about everything even medical needs of horses, carry an entire pharmacy and will treat my horse if the vet can't come or if he can save me $$

They are also my neighbors, in a tight nit community I have boarded there 10 yrs. Taught me how to saddle bridle and mini lessons of handling horses (just mentions things). Gave my 8 yr old his own horse, best darn horse I ever met, my kid cantered and flew on that horse for 4 yrs. You know kids, there is only one speed for a horse, fast as it can fly.

Issue: Steve cannot muck out stalls daily; his wife Susan is having a hard time with her leg and back can't do physical work. Steve works round the clock and can barely keep up the place. They have lost so many boarders, they can't afford to hire anyone

Stall Management Question

My 2 Mares share a stall, live outside most of the time, come in daily 3-4 hours a day for feed; my Paso likes to lay down and snooze she is too hyper to lay down in the field. She adores Steve; they have their own communication thing going on.

Barn is old but solid as a rock, many stalls to use for temporary feeding. He can't muck these out daily. This is what he does - and I dont know if it is OK

Instead of mucking out daily, he rotates the stalls, dries out the poo poo, packs it down, layers bedding ontop. He will muck out a stall when it hits about 8" or so.

Q: Is this method OK for my horses? I know humans would love to tuck them into a pretty stall, santized, pretty bedding, so many barns are for humans, not horses.

The horses have air flow and can stick their head outside, there is also air flow through the entire barn.

What do you think? I have no idea if this is going to cause my Mares health issues.

Now, I have a bad back and new (nasty knee replacement) so I am not much help.

I do have a 185 lb rock solid muscle 16 yr old boy the same one that enjoyed Steves personal horses, the one he would never lend out for 4 yrs

My kid can clean out that stall in 1/2 hour or less and haul away all 6-8" of packed poo poo.

He can also feed all horses fast, picks up 50 lb bails, puts the in wheel barrel, cuts the strings, pitches out the piles (many piles so no fighting).

I know Steve doesn't want boarders doing this, he has pride and his own ways.

If this were your horse, would you muck out the stall? Sanitize it? Is the method of drying the poo poo and layering bedding safe?

I can get my kid in there when Steve is not home; Susan his wife will let me

Your technical advice, not that it just isn't pretty, is greatly appreciated.

Thanks