I've been trying to record two same name/different channel shows (both shows occur at the same time). My reasoning is similar to yours in that the channels are in different metro areas and one may be flakey. I am running the server on a Raspberry PI boot image so I have no way of setting up two servers on the RPi.
Just tried setting up recording the show on the first channel using the UI. Modified start and stop times by ten seconds but I don't know that is necessary.
Then I tried setting up a PASS recording of the other channel show (same show, original start/stop times) .
Both recordings show up (as highlighted) on the UI and appear in the web UI as being upcoming recordings (along with all the other future occurrences of the Pass show). I'll need to cancel those future PASS recordings.
It will be interesting to see what happens when the show time comes around (noon). Next I'll try this with two PASS recordings and see if that works.