Chapter 1: Of the Beginning of Time

[Aiwendil]

Actually, looking into BoT-15.1 further, I may have found the solution.

In AAm* (and in at least one emendation to the full AAm), Tulkas's wife becomes, instead of Nessa, the newly introduced 'Lëa the Young', a Maia. I had noticed this, but ignored it because the Valaquenta, which postdates AAm*, again has Nessa as his spouse and no mention of Lëa . However, in ignoring these changes I overlooked this:

It is told that in that feast of the Spring of Arda Tulkas espoused Lëa-vinya, fairest of the maidens of Yavanna, and Vana robed her in flowers that came then first to their opening; and she danced before the Valar...

So it seems to me that the idea now was that flowers did not bloom when the lamps were first made, but first bloomed at the time of this feast. I think we have no contradictions, then, if we do this:

BoT-15.15 And it is sung that in that feast of the Spring of Arda Tulkas espoused Nessa the sister of Oromë, and Vána robed her in flowers{,} [that came then first to their opening;] and she danced before the Valar upon the green grass of Almaren.