I think it got quite hot, the full dalek went from full of the above to 1 foot high in a few days!
When I filled first time I put layer of soil in and it went down a third then filled it up again.
Week later it was nearly down to half again, so filled again with grass, sawdust and a few greens..
Filling whole bin in one go does get the heat going as the more you add in one hit
increases the heat a lot.