Excellent factual article as usual Dan.
One issue we in the experiential world face, by nature, is the lack of standards and uniformity, or conformity.
This is especially true with our FWF systems.
If one decides to install a crankcase return venting system, I would hope they document, placard, or in some other way call attention to it. Your airplane may not always be your airplane. It may fall into the hands of an uneducated (read some of the maintenance post on VAF), or ignorant owner who has no idea he has an extra maintenance item to look after, one that may bring an airplane down.
Off the top of my head, I can’t think of any other accessory in the FWF system that has this kind of potential to catch the unwary. If I was going to install a system like this I would make the bypass reed mandatory.
For those that do install a system, don’t assume a future owner would have as thourough an understanding of the airplane as you do, even if they should.