Yes, the cardboard seals on the bottles are absolutely worthless! ... And the use of a separate, cardboard disk instead of a molded conical lip in the cap makes absolutely no sense. .... I assumed it was some weird, German cultural thing. But the last Ilford chemicals I bought were the same way.
Not at all. I do not remember having seen cardboard seals at other products the last years. But next to moulded lips I see foam-sheet seals.
Substituting cardboard by foam should not be a problem.