I guess, now that I have fast-enoguh-draining mix, they have become easy for me too ... but for 2-3 years I couldn't start any Salvia from seed, annual or perennial.
I think it also helped me a lot when i started pre-soaking salvia seed despite their small size.
You're almost certainly right: it HAS to be easier to start a whole extra tray of Salvias from seed, than to maintain even a few potted plants for months indoors under lights.
And next year I'll be smarter about pushing them from the trays into soil earlier.
