Yes, this is one workaround for the limitation, assuming the guides overlap sufficiently. If you’re very lucky, your cable provider carries all your local OTA channels. This would certainly work for the example above. You can also use pseudo-tuners such as xTeVe to aggregate the different physical tuners (and other sources as well). I’ve also seen on these forums where users trick Plex Media Server into adding two different guides by adding multiple tuners simultaneously in multiple browsers.
These are the workarounds I was alluding to above. There’s also a feature suggestion somewhere for the ability to use more than one guide source:
