How should I set the "Swing" on this thermostat? (RiteTemp 8022C)

Shalom

Gas heat, single pipe steam. (For system details see my older posts.) Pretty sure this thermostat is a Home Depot house brand unit.

When I got this house, years ago, I replaced the old "round" thermostat with an electronic one, because I vaguely remembered that you're supposed to set the temperature down at night. Then the kids came along, and I basically set the thermostat to hold one temperature and left it that way, because babies don't go to work so there wasn't any unoccupied period to let it cool down.

Now that I know more than I did then, I wonder if this is even the right thermostat for a steam system. There's no setting for cycles-per-hour; instead there's a function labeled "swing" which is described as follows:

"Swing setting determines the temperature difference from ON to OFF that the thermostat will command the heating/cooling system to run. (...) The furnace will cycle more at the lower numbers as it tries to keep your set point constant."

This seems to be inversely related to cycles per hour: the lower the number, the more cycles, but it's not a direct relationship. The default is 3; I think what happens is, if you set it to 68, it will go on at 67 and keep going until it hits 70. I think I had it set lower than that, once upon a time, but the batteries ran out and when I put the new ones in, it forgot all its old settings. (Supposed to hold it for 30 seconds without batteries, but the old ones were so dead that it didn't even hold 5 seconds, so I had to reprogram everything, and I can't remember what I had it set at.)

So what you recommend? Set it lower, leave it where it is, put the old "round" thermostat back (if I can find it), etc.?