Firstly I want to say great diy post , Infact I recently did this to my e39 m54 due to 2 failed ccv's, and the car seems to idle and run better as a result, but I do have some concerns about the amount of vacuum this pcv set up creates, I noticed when the car has been running or when it's just been shut off the amount of extreme suction/vacuum the oil fill cap & dipstick tube have upon them, granted the rings need vacuum to seal properly but is this much vacuum overkill and could it cause problem down the road, like valve cover gasket issues etc?

And lastly have you had any problems with your mod since your last post?