Partial OTA channel scan

Being in between two or three OTA markets means I have to frequently reposition my antenna to tune in certain channels. This usually means dropping reception of other channels in the process. The all-or-nothing nature of Plex’s DVR channel scan means I have to rescan every time I reposition my antenna. My TVs allow me to do a partial scan: meaning I can specify the frequencies to scan. This allows me to scan for specific channels/frequencies which can then be merged with an existing scan (rather than overwriting it entirely).

Something similar to that would be handy for me for Plex’s Live TV/DVR feature. Or even a merge-new-channels-found-into-a-prexisting-scan scan feature.