Oversized calcium reactor just means it'll go longer between maintenance.
I tried to make an aquamaxx reactor work for me, but even set extremely conservative, it destroyed my elevated pH (8.3-8.7 most days) and was dipping below 8.0 before lights on. I gave up on it. I was just wanting to add about 1dkh/day on top of the kalk, so it shouldn't have been that bad. Idk. I'm just going to continue kalkwasser and dose lye overnight instead. Too many people breathing in the house I suppose.
The difference in growth at much higher pH is phenomenal as well as the reduction in things like cyano and alage growth. Turf scrubber still produces well, but less grows in the tank.
With the calcium reactor suppressing pH, alk demand plummeted. I don't see why people are scared of kalkwasser.
Don't put it in an ATO bin, nor use a cheap doser. Also be sure the line cannot create a siphon, no back siphon. Solves many of the problems of the past. Of course, a master flex pump is likely better, but the kamoer is solid. I have 3 of them. 2 v1 and 1 that is wifi. Tubing lasts about 6 months or more if tension is set right and slower flow rate. Replacing the rollers as much as they recommend is unnecessary.
Buy a continuous duty doser like the kamoer fx-stp and drip saturated kalk 24/7 at a set rate. Adjust ml/min. As needed for seasonal changes. Your ATO is now basically obsolete. If something leaks, or tank loses water, you won't have an ATO dumping in rodi. Just that steady slow kalk drip.
You can use a kalk reactor if a 60 gal. Drum isn't going to work, but on such a large tank, I'd imagine its not as much a concern. The doser can easily push 20ft+ if needed.
You can use a versa doser, but many more complaints on those.