My first useful contribution here: I designed a 3d-printed adapter for the Flextail tiny pump 2x to the boston valve that can open up the check valve part and let air flow through freely. Print it with the narrow part down and the wide part up (upside down). If the flextail pumps have the same diameter output (which I suspect is true) it should work for all of them.
It needs some post work. You have to drill out the holes in the nozzle – they go 10mm deep – with a 1mm bit and then glue insert thin paperclips or pins and cut them to extend 4-5mm above the surface. Alternatively, you can heat up either the pins or the holes with a hot air gun and press them into the holes (preferred if you can manage it). I used stapler pins folded empty, which is just about the right thickness on my print.
Add a small dab of plastic/epoxy/hot glue to the ends if you’re worried about sharpness. Finally, remove the valve from its seat, insert the adapter, line up the pins with the holes (look under the check valve on the other side to confirm), and push through. Mark off matching points on the adapter and the valve with a notch so that you can line up the pins and the holes easily from then on.
The pins could be a little flimsy, so you might have to carry the adapter in a pill case or something.
