I just got a bunch of cuttings, and I had to remove some leaves low down on the stem to get good contact w substrate. Is it worth laying these leaves on a bed of substrate like sedum or crassula?

None of you have tried this? Preposterous!
If you tried it and it didn't work, tell me about it...

I have no experience with that plant, but I would refer you to a highly recommended book by Kapitany and Schulz called Succulents: Propagation. In that book they describe S. mandraliscae (now apparently a variety of Curio talinoides) as "low strike rate" when propagating from leaves, which apparently is best done in autumn or winter, and "Leaves grow roots but seldom produce plantlets". There's apparently another "blue chalk sticks" called C. repens about which they say nothing.

So try it and keep your expectations low.

Thanks Baja.
Even with my experience, im running at 50% or less for "easy to propigate from leaves" at high season.

In the trash they will go... its only a couple leaves. Thank you for saving me the space and evergy.