Starting seeds in 50% EWC and 50% pumice?

I was reading that seeds sprout really well in worm bins, and I didn't have much soil, so I made a mix of 50% of my own EWC from my worm bin, and 50% pumice I had.

The worm bin I started 8 months ago with 100% sphagnum peat moss, and I've just been burying the food an inch deep, so not sure if the top I skimmed off was pure EWC or if it had some peat in there as well...

Will my seeds do OK in this mix? Or will they get burned somehow?

Seeds are delicate. If you bring over bad bacteria or fungus they could get fd up. Personally i would never start a seed in anything 'hot' or fertilize until they got a bit bigger