The whole idea of the small tank with a CSV, is that the CSV eliminates multiple pump cycles during longer term uses of water like showers and sprinklers. So even though it may cycle when a single toilet is flushed by itself, the total number of cycles is still less than without having a CSV and using a larger tank.
The pump doesn’t actually get an extra cycle every time a toilet is flushed. If you flush just before starting the shower, while the shower is on, or very soon after the shower is turned off, there is no extra cycle because of the toilet. If a toilet is flushed while the washing machine is filling, someone is brushing their teeth, or any other water is being used, there is no extra cycle because of the toilet. I mean, how many times a day do you flush a toilet while water is not being used somewhere else in the house before, during, or right after the flush? This doesn’t happen very many times per day, and would also be a giveaway that you don’t at least wash your hands after you flush. L
Life of the pump and system is all about the total number of cycles. Even if the pump cycles 30 times a day for toilets flushed all by themselves, that doesn’t add up to much. And the CSV will make up for those cycles by eliminating 3 to 6 cycles for every shower and dozens if not hundreds of cycles when running a sprinkler or other long term water uses.
However, the CSV will work with any size tank. 30 flushes per day would use 48 gallons of water. So if you have an 80 gallon size pressure tank (25 gallons of usable water), during the worst case it might save 28 cycles per day. And that is only if the toilets are flushed 30 times a day without any other water being used at the same time. The tradeoff is extra cost of the big tank, extra square footage or space to put the big tank, and BTU’s for heating the big tank. You also would have to live with decreasing pressure for the first half of a shower, before the pump starts and you finally enjoy the strong constant pressure delivered by the CSV.
With a small tank and CSV the pump is on quickly and you can enjoy constant pressure during an entire shower. Large tank or small the CSV system is far superior to the variable speed type pump systems (or VFD’s) many pump installers try to push on their customers to increase profits.