I don't, and can't speak for Alembic, but it's a true statement... the time to replace inlay is while a total refret is underway.
I have always wondered if the 'disappearing pearloid' ovals could be carefully removed, and re-inlaid with a light-colored backing. I have long suspected that the ebony backing, and a thin layer of glue is what made them seem so translucent. Aluminum foil backing... or even silver paint in the cavities might make them *pop*.
Might try it some day.