I read a thread you and a few folks were trying with the bladder inside a hard tank with pressure collapsing the bladder good idea for steady feed.
Back in the day we had a diaphragm type pump using the engine cycle to feed fuel nice and predictable and would monitor the flow as demanded just not practicable to fabricate a micro version for most folks.
Yes I tried a few tricks even tapped and put a pressure nipple on the back plate but the pressure was too great the nipple was allowing too much into the tank and setting the needle was fussy fussy. Going to the clunk tank with just a breather tube seems to be giving me predictable runs each time the trick is to lean out a hair on the ground as air rams into the vent tube at speed pushing more fuel. I need a smaller hole in the nipple to use crank case pressure the nipples I had bought have too much ID so maybe install a inline metal tube to pinch down to just allow a tad in. The one way valve holds pressure allowing it to build up in the tank and the wee engine responds to this quickly richening up so really need a muffler with a tap perhaps. I bought a G-Mark .030 for 75 bucks from Tim to try on this plane its in the mail at the moment comes with a nice lil RC carb and muffler I can tap for pressure. May save that engine for another project will see how it goes haven't given up on the crank case pressure yet just need to fab up a restrictor tube next. I want every last drop of fuel pushed out of the tank to allow acro even when the tank is down to 15% fuel.