Yeah, I have used a SVEA for almost 40 years (boy it doesn't seem that long.) Anyway, when I traded for some flies I had tied, I got a fuel bottle and a pair of caps from Optimus. The one had a small tube for filling and a hole in the back for stopping the flow. I always made it a practice to fill after every use. In warmer weather, I didn't bring the pump. Rather, I used the tube, about the size of a bic pen cartridge, to pour it into the so called "spirit cup." I never had to prime more than was needed once I got used to it (takes four or five uses.) After I switched to a coke bottle, I would just strip some 12ga/10ga wire and insert it tightly into a spare top use the vinal casing as a fill tube. I tried to glue and epoxy it, but that failed after several weeks, so the mechanical seal actually worked better.
The Midi pump really doesn't save fuel because it doesn't really fill the cup. When it is leaking down the side, it is a whole bunch easier to light. While lit, I would turn the valve off. As the flame died off, ie, till it was almost burned out, turn it on to run. I never used the fire paste.
Generally it burns about an ounce per day, unless you are melting snow. 1L in the morning, 1L at night with about 5-7 minutes of "simmer". A 16 floz bottle only weighs about 14-1/2 ounces which is enough for just about 16 days...closer to 7/8oz per day. Since the fuel bottle was used for both priming and cooking, that was already figured.