Your idea is sound. In fact I have 5 lines that do not have gravity vacuum to their advantage and those lines are surprising to watch the flow. My most surprising 2 are lifting sap a net lift of 5-7'. My vacuum is not a diaphragm pump but they work well, especially when you have some gravity working for you too. In my case I just did it as a low cost non scientific experiment. Those 2 lines I spoke of above start in low areas on the other side of the driveway going into my sugarhouse, line 1 had 19 taps but two of them were on red maples and as my reds budded I removed those two. There is about 400' of tubing from the lowest tree to my mainline. All of my drops are 5/16 and on these lines the lateral is 3/16. From that lowest tree the tubing gets sap as the tubing rises about 4' to a sugar maple beside the driveway. From there the 3/16 goes up from chest high to 14', then across the driveway to another tree and then it slopes down the mainline which is on 26-27" vacuum if leaks are in check and it connects to the mainline there. The other line started in an even lower location and about 200' (of tubing) farther. That was all reds and was also removed from service as the reds broke bud (the first hint of green). That line also got to the same tree as line 1, rose up, crossed the driveway and sloped down to the same mainline, tying into the main adjacent to where the other line had. That line has 30 taps on it, all reds, and the sap flow was greater than line one (11 more taps before any were removed).
While I have no documentation or scientific data to let me know how much sap I gained from those 49 taps, it was a success in my eyes. To use conventional methods to tap those trees with tubing I would have needed to install a mainline (about 450'), likely 2 sap ladders and lots more saddles to tie the laterals to the mainline. The cost would have been far higher than what I spent to get the sap from those 49 taps. As it was I used 2 saddles and about 1000' of 3/16 tubing. The taps and drops with tees I didn't factor in because either method would had used the same number of those.
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.