Your turbo setup is almost exactly like mine - except yours is installed
If the hose to the ground isn't enough of a vent on your setup, then I don't know if a vented catch can would do much better. You might be best off going with a catch can, but instead of a vented catch can, go with a hose to a vacuum source instead of a filter. If you do this, be sure to use a check valve in your vac line so air can only flow one way. This way under boost, you won't be pushing air back up into your valve cover.
I'm kind of surprised that the open tube to the ground didn't work well enough for you though. Since a vented catch can is more restrictive than an open tube, this means I'm gonna have to change my setup as well. Keep us updated on your setup and I'll do the same when I change mine.
I am going to do some more research on the exhaust slash cut method. There's a lot of variables that have to be correct for it to work right, but you get the best of both worlds. You get vaccum, and that dirty air gets sucked through the exhaust instead of in your intake.