Your free to believe whatever you like but this stuff is not magical or even mysterious and there is a reason why nobody breeds spider X spider or Pin X pin etc. You are also making the assumption that everyone has always been honest, which most people realize has not been the case either.

Hiding behind the "we dont know" is a tad convenient, as with a lethal gene that dies early in development, the proof you demand would be impossible to get. Over the years when this argument comes up I usually find it a amusing that those who argue that Spider is dominant avoid doing that pairing in their own collections.

We now have a whole group of genes, that when paired result in severely damaged or dead combos (spider, woma, hg woma, sable, champ etc) and of these the spider is by far the MOST damaged in heterozygous form. So even though we know that the spider gene is clearly lethal in several combos, AND there is a complete lack of any evidence for a viable homozygous form. I guess I dont understand your relentless optimism on the subject.

On the issue of Dominant genes, I hardly think the "daddy" gene counts as it looks normal in both heterozygous and homozygous form. On the congo, can you even define what a "congo" looks like.... me neither.
Your then left with one supposed homozygous pin when there should certainly be many more than one. call me a skeptic I guess.