A relying party that wants to accept national eID across Europe either builds one integration per country or picks the few that are worth the effort and turns everyone else away.
Not "do you support eID". It is how many of the schemes your actual customers hold, and what happens to the customer whose scheme you have not integrated.
National eID schemes and the EU digital identity wallet aggregated behind one interface.
The relying party asks once; the user authenticates with whichever scheme they hold; the answer comes back in one shape regardless of which country issued it.
Not established for a public claim. Which schemes are currently integrated needs a source before this section carries a number or a list.
A customer whose national eID exists but is not integrated drops to a weaker fallback route by default, a decision nobody made on purpose.
Which schemes are offered, and in what order, set per market.
A customer whose national scheme is not integrated drops to a weaker fallback nobody chose on purpose.
Which scheme was used and at what assurance level.
One interface behind schemes that each change on their own schedule, rather than a per-country integration your team has to maintain as each one updates.