I think that changing "dross" into "ore" undermines the meaning quite a bit. Dross is the waste product after the metal is extracted from the ore, as you know, so it's hard to make sense of the line as translated. As with cake, you can't smelt your ore and have it too.
Here's a suggestion that I'm not entirely happy with, since it uses a slant rhyme, but it may be worth considering. And I've thrown in another suggestion for L1, which you can have for no extra charge:
There's just one thing that's not. Oblivion.
God, who saves the metal, saves the dross
and codes in memory for His revelation
moons that will be, and moons that will be lost.
PS-- I have a further suggestion. Change "revelation" to "retention," which I think suits the meaning better and also is a step closer to being a rhyme for "oblivion," though still not very near.
.
.