I'm not real clear on how that would work with the pump only cycling once per day when the water is on/off all day for toilets/shower/sink/etc. even with a larger pressure tank?
The Cycle Stop Valve only keeps the pump running all day if you have water running all day. Even with a small tank the CSV only lets the pump cycle maybe 30 times a day for normal house use, which is the same as having a big tank and no Cycle Stop Valve. The CSV is most advantageous when using water for long periods of time. For instance, the CSV only lets the pump cycle once during a 50 gallon shower, instead of a 32 gallon size tank dumping 8 gallons of water about 6 times as the pump cycles on and off. Run a sprinkler in the yard for an hour or six and the CSV saves hundred of cycles.
The only pressure control you have now is a switch that turns the pump on at 40 and off at 60. With a large enough tank this has always been the most reliable way to control a pump. The only problem with a pressure tank only system is the repetitive cycling. Cycling maybe the only problem with a pressure tank system, but cycling causes numerous problems. The life of everything, and I mean everything, including the pressure switch, check valve, tank diaphragm, start capacitor/relay, and most especially the pump and motor is greatly shortened by the pump cycling on and off. Even sediment in the well can be caused by the well surging up and down as the pump cycles on and off.
People who have been using pressure tank only systems their entire life without issues, are just lucky, or just don't know what it is like to really not have any issues. They think the pressure constantly changing from 40 to 60 over and over in the shower and all the problems caused by this is just normal. Once they experience constant pressure for the first time, they realize they have been having issues all their lives, they just didn't know any better at the time.
If an "ounce of prevention is worth a pound of cure", a Cycle Stop Valve will add a pound of cure and prevents anything from going wrong that could go wrong. Not my first rodeo. Been doing this for over a half century and heard all the stories. Some people tell me they have no irrigation, no long showers, or anything that would justify adding a Cycle Stop Valve. Although even short showers have much better pressure with a Cycle Stop Valve. These people don't know any better than the pressure going up and down all the time and have gotten use to it. Then one day they call me and are mad. That pump cost a lot of money and should have lasted longer than 6 months or 6 years. So, I go replace the pump and get it working again. However, the pump will not stay off when it gets to 60 PSI. It just drops to 40 and cycles on again. Walking around the house I find a garden hose running across the fiend and watering the weeds. Seems the kids were playing with the hose last week and just threw it in the weeds and forget to turn it off. A few days later the pump is toast and the owners are made at me for selling them a "cheap pump". After refusing to install a pump without a Cycle Stop Valve I no longer have warranty issues or mad customers. The CSV prevents anything that could go wrong from being able to go wrong. That hose in the weeds would have made a lake after a while, but it would have never hurt a pump controlled with a CSV. The pump would have just run constantly until someone turned off the hose, but it would never hurt the pump.
If you could make the pump run 24/7/365, it would last much longer as pumps are made to run continuously, not to cycle on and off. I have one filling a stock tank that hasn't turned off since 1996.
"I don't have much room on top between the tank and ground level -I might only be able to put about 6" of dirt without mounding it."
This problem too can be solved with a Cycle Stop Valve as a large tank is not needed. You would get even better service with a CSV and a 4.5 gallon size tank, which would fit up on the wall, not take up floor space or be down where it can get wet.
