The reason for matching the characteristics of the two valves is just make life easier. Once matched you do not need to do any corrections to compensate the open/closing time, just boost the raw signal and your are done.
On the other hand, you use any un-matched valves you need to spend time to play with the electronics to match the flow (correction tables). Either way, there is no short cut if you want a system that mirrors the fuel flow with a reasonable accuracy.
This is of course not needed if you are going to make your own map as mentioned, a XY grid. But the drawback would be mapping time the dyno, everytime you alter the meth map, you need to alter the fuel map so that you can consistant octane/cooling balance. it will be time consuming.
We did look at all algorithm and decided to track IDC - not perfect but very simple to tune.
The valve can work 10Hz and it will be a smooth flow. The valve a quite large due to ther 1/8 BSP fittings on each side. We can intergate a nozzle on the lotlet side of the valve - if you like, I post a picture here. These FAV (fast acting valve) is quite new, I don't have the price yet - depends very much on your specifications. We haven't planned to sell this valve separately commercially. For occasional project as yours, there is no problem.
Sounded like something good is brewing...