Poured door transition - Safe to dig around?
If, as it appears from your pictures, this is a solid block poured in place of the blocks that are not there in the door opening, on top of the poured foundation wall, 6-8" overhang that thick is not a particular concern for digging away underneath - it's not going to fall off if you're not taking a sledgehammer to it, even if it is unreinforced.

If it stuck out more, or if it was thinner, there might be a cause for concern. Here, no worries. Or, if I'm seeing things wrong and it's really just scabbed onto the face of blocks (can you see the backside of this in the crawlspace?) but in that case I'd expect it to fall off anyway, so it seems unlikely.

Compact the drainage rock well when filling this area would be the only special attention I'd pay to that.