Wow, all good responses... very appreciated.
I guess I should bound my input/request a little further. When I wrote this, I was originally thinking of what first edition referred to with respect to Advanced Cultures, specifically (as quoted from the book):
"Experienced players and Loremasters will notice how several characteristics of both the Rangers of the North and the High Elves of Rivendell break some of the limits to character creation set by the core rules."
And it continues
"Now, neither a Ranger nor a High Elf fits the definition of ‘first-time adventurer’. The Dúnedain of the North roam the land of Eriador hunting for their enemies, and may
travel much farther if their duty requires them to do so. If there is anything close to full-time heroes in Middle-earth it’s the Rangers. Similarly, even the younger High Elves have witnessed hundreds of years of history and possess superior powers."
In other words, framing it in this light, a few additional/expanded spells or spell casting ability, via... new advanced culture(s), or new calling, or new reward(S), or new virtue(s) could be (and should be) given the same reverence.
So continuing to wax philosophical... some examples:
1) Under the guise of experienced play that can be handled appropriately verses right out of the gate (e.g. deeper into a campaign when more "horsepower" is required).
2) Maybe access to something like an advanced virtue or reward that only actives when a specific prerequisite is met (e.g. at a certain advancement milestone or wisdom/virtue level).
I do not claim to have the silver bullet of what it would look like - but in all cases:
1) I would like something that does not "break the game" anymore than the Rangers and High Elves did (refer to the above), yet, offers the scratch for the "a few more spells" itch
2) I would not want to D&D-ify the game (although I think it would take far far more than a few more spells to accomplish that)
Just some expanded thoughts.
Thanks and Take Care,