Glad to hear u did a purge of your new spa!
In general the recommended levels listed in the sticky I posted above are just like the other tfp recommended levels - scientifically researched recommendations tested in the real world by real owners to promote the safety & longevity of their users/equipment. I don’t think they’re all that far apart from your manufacturer recs.
The pool store recs. are a whole nother subject
You could try to meet in the middle if it makes u feel better. Especially since you’re spa is new & i’m sure the warranty is a concern for you.
If you continue w/dichlor use u will be having a fc/cya issue once that gets past 30-40 ppm range.
here’s some more info on ozone which can cause ph rise so maybe that’s why they allow a higher ph w/ it in use.
Ozone Systems - Further Reading
Your particular situation will determine whether or not u feel its a good fit for u to use it.
As far as The uv Is concerned i am not well versed in the pros or cons of such systems.
@JoyfulNoise or
@RDspaguy likely can help u out with that decision.
For what it’s worth - i do not have any of the uv/ozone stuff. I use the dichlor then bleach method w/ a drop in swg along with the other recommended levels in the sticky thread.
Every few weeks depending upon splashout i use dichlor to shock which also replenishes my cya. The rest of the time my swg keeps Fc levels quite consistent unless i have a longer soak or larger bather load than just myself & for those times I bring it to shock level with bleach. Upon startup I get my ta 50 -60 , add 30ppm borates & bring my ch to 150.
My ph stays @ 7.5/7.6 unless I replace a lot of water.
it’s really not alot of fuss.