Hi valth than you for this nice post, which smells by forest.
Myself I need not bother to bend to distinguish between these two mushrooms. They are quite different.
Other problem is Boletus badius which is much more like Tylopilus felleus, but even thus 90 % can be solved just by one look.
The reason is easy. For me is Boletus badius main interest, because Boletus edulis is rare. Czech republic is not Norway. I have heard wild stories about mushrooms in Scandinavia. Here in the Czech republic almost everybody picks mushrooms.
Happy walking in forest to you!