Great summary. Small comment on FIDO2 tools - Token2 now actively helps to develop open source vendor-agnostic FIDO2 tools (check keyroost for desktops and librekeycompanion for mobiles) - so you have one (or two) fully open source tool(s) to manage any FIDO2 key
Two FIDO2 keys, same standard, same price. One asks for a PIN, the other just needs a tap. On most models no PIN is set at the factory, and whether you are asked at all is usually the website's decision. We read the manuals from Yubico, Token2, Nitrokey, OnlyKey, Feitian and Google.