Mason County is about 60 miles NNE of Lexington, and Dayton stations could easily be received in many parts of the county, depending on topography. Without taking the effort to look at the various Television Factbooks, I seem to recall that WHIO was carried on cable there for some time.
Before they went full-time with CBS, WKYT only carried some CBS programs. I don't know what they did after they went full-time with CBS. I don't recall WCPO pre-empting CBS any more than any other station would have at that time. In the 1960s and 1970s, it was common for network affiliates to air a movie at least one night a week, in lieu of network programming.
Before the advent of satellite, just stating the obvious, carrying network affiliates from different markets was the only way you could have much diversity on a cable system. That, coupled with the tendency to pre-empt network offerings more often than today, lent more variety to cable lineups, as well as time-shifting. The networks started cracking down, and now pre-emption for local programming is relatively rare. Fox in particular has a very low tolerance for it.
When Lexington was a 2 station market, WKYT only carried Captain Kangaroo and the mid morning sitcom block ( Beverly Hillbillies ect.) from CBS.
Primetime during the Taft and ABC years was solidly ABC.
WLEX carried some CBS soaps, and cherry-picked the most popular shows at the time (Think Andy Griffith, Gomer Pyle and so on). Full clearance CBS for those of us in Lexington came from Cincinnati or Louisville.
After WKYT returned to CBS under Garvice Kincaid's ownership, he was all about localism.
Preemptions were common on WKYT then.
Kincaid was a business man first and foremost and realized he could make more money selling local ad time. Plus he dumped a bundle into the new studio/transmitter site there on Winchester Rd. that had to be paid for.
WBLG (WTVQ) ran a close second even being the new ABC affiliate.
WLEX seemed to be the least preemption happy of the three.
Those of us that still had our outdoor antennas were greatful for that.
Then I was a kid in elementary school and some of my favorite shows then were on CBS, Lost in Space, Wild, Wild, West, My Favorite Martian none of which had clearance in Lexington.
FWIW, WLEX received CBS OTA from WCPO.
WKYT received ABC OTA from WKRC and CBS from WCPO, during the Taft years. It showed, too. Shoestring budget and operations.