using relay lists stored in kind 3 vs kind 10002 events is the biggest pain in nostr client interoperability imo. not sure how we solve this since people can't seem to agree on what should be the source of truth even though using kind 10002 is the only documented way of saving a relay list.
Discussion
There is clients that "work" the old way, with the dev havin no spare resources for this, so they won't fix it. For the sake of a good standard, clients should not support old standards but users will blame the clients that don't find their relays for being buggy, so client devs will add this interoperability.
Yesterday or so I saw there's a project that documents what client doesn't play well with another client. This kind on project can give the users a perspective on who's at fault here.
Maybe we will have tools to upgrade profiles so clients can just implement the current nips and not care about legacy support across all of them.