It's always tough when you've got a bunch or frequencies where you only get the airborne side. If I am not mistaken, Ron feeds one from his pop's out east and the other from home in Nassau. The gem in his collection is 134.0, where he can get the ground from his dad's, and if it were me I think I would at the very least have a dedicated radio for that one, run the feed out there in stereo, put that freq on one side and the kettle of fish on the other. At least that way you could get full QSO for one of these many channels, in fact if I had to choose between streaming either a dozen one-sided channels of mostly very brief acknowledgements of instructions or a full air/ground channel that occasionally is dead for hours at a time, I would still choose the latter. Even if you didn't want to run stereo, I would still use two radios, one scanning and the other on 134, and brew up a simple audio priority switch to pad down (not fully mute) the scanning radio whenever the squelch on the fixed radio is opened.
Even without an active device you can make a simple three-way mixer with a handful of resistors and a small chunk of perf-board that will give left, right and center audio with a stereo feed, which is what I use on the HF feed. We're not talking about hard left and right, more like 45 degrees either side, which makes things less disorienting. Using three HF receivers I feed 5550 left, 6577 right 24/7 and 8846 from 9AM to 8PM in the center, and it is rare that two frequencies are in use at the same time, let alone all three, and only when they are switching over as the bands go up and down.
Even with a mono, single channel feed using blended audio, if you group frequencies between two or three radios such that all the channels associated with certain arrivals or departures are allocated to one receiver, with different receivers becoming more active at different times, you will still be far better off than with a single radio scanning a dozen channels.
Of course this is all IMHO