The main reason most say i need stabilizer is my cell will wear out quicker. Everything i have read says that when your CYA increases, you need more FC. My pool is beautiful, at 50% of SWG level and very low FC levels according to my strip tests, maybe 1 or so.
Im not sure youre getting the full picture from your reading so I'm going to try to paint it
The reason you need some cya in general terms, swg or not, is that in addition to buffering FC it also RESERVES FC for residual use in cases where there is a sudden high demand (intense sun, urine loss, bacterial contamination) or erroneous drop in FC...eg in the case of swg malfunction, cell age over time, power outage, etc.
The problem here is that without a proper test kit, you have no idea right now what your cya REALLY is to debate what level you run things at, or reliably predict that people who swim in your pool are protected from transmission of waterborne pathogens, particularly if swimming at night with swg off, where swimmer load can easily consume the FC if kept so low.
So the question of whether you can run at 50 or run at 70 is academic without testing, to my mind
Check out
TFTestkits.net for a tft100 or Taylor k2006.
Once you know your accurate water parameters, and have the ability to reliably test, you're in a better position to experiment with run time, levels, etc.
If you prefer to run at 50% production at a low cya than say 10% or 20% production for the same 18 hours, that's totally your call. But you'd have to clean your cell less often, or replace it less often, if you were running it at a lower percentage of production.
Your concern about running a higher FC level in accordance with a higher CYA level though in practice might not be the way you're thinking.
Eg at 70 ppm cya with a run target of 3-5 pm per TFP reccs for swg, in terms of production once the FC level is established only takes the generation of about 1.5 ppm per day in my pool, which would be I think about half your % production if I were running your 18 hours.
I don't know the gallonage of your pool, but we're both running an aquarite t15 so your maximum capacity of chlorine gas production is around 1.5 lbs daily...using pool math, you can calculate how many ppms of production that is for the gallonage in your pool. My rough guess would be that you're using more capacity to produce chlorine than I am to keep yours on the edge of 1 ppm, while mine is at a safer 5 ppm - I'll be fine if the power he's out, my nephew pees in my pool, or my elderly guest shares cdiff or crypto or giradasis.
Because in terms of maintenance (mine starting at 5, yours starting at 1) you will have constant loss from burn off at lower cya, while I will have considerably less actual loss.
Make sense?
Keeping FC at 5 with 70 cya in my case requires production of about 1.5 ppm daily, about 15%-18% of production capacity on the t15, which in my 23,000 pool has a production capacity of 7.8 ppm.
Hope that gives you a different way to look at it. But seriously, get a test kit, and then lets compare notes