Likely some have, but it will depend on how many leaks are in the system. Technically it should work, but only if leaks don't render it useless. You will be best off if you have a recirculation line, from the lunchbox output, back to the mainline, close to the lunchbox. That works best if you install a valve in the recirculation line, you just want to keep the diaphragm wet, not over run with sap.
How many taps will be on this system?
Dave Klish, I recently ordered a 2x6 wood fired evaporator from A&A Sheet Metal which I will be converting to oil fired
Now have solar, 2x6 finish pan, 5 bank 7x7 filter press, large water jacketed bottler, and tankless water heater.
Recently bought another Gingerich RO, this one was a 125, but a second membrane was added thus is a 250, like I had.
After running a 2x3, a 2x6, 3x8 tapping from 79 taps up to 1320 all woodfired, now I'm going to a 2x6 oil fired and a 200-425 taps.