My other car is a MINI!!!!
if you are getting compressor stall, it would imply that the diaphram in the DV is split.
my forge DV with a stiffer spring opens EVERY time I back off the throttle, regardless of how much I applied it, and the standard one should do the same, as it feeds from the manifold. As soon as you close the throttle plate, there is a vacuum within the plenum, and this should open the DV.
I'd imagine your diaphram is split, or perhaps starting to split, hence why you get a slight dump after using more boost.
Replace it with a standard one by all means, but don't expect it to last forever.
I'd advise a forge 007P piston recirc valve, it's just about THE most popular DV on the 20vt engine, and there's a very good reason for that!