OK, with two minor tweaks the socket streams started to behave better for me. The whole suite passes sometimes, although the results get often spoiled by transient failures which suggest a race condition in transform write stream. I think it's the the same one I occasionally see on VW side although it's quite rare there. But the fact that it comes up more frequently on Squeak side should help figuring it out, since it makes it more reproduceable. We'll see.