Has anyone tried to propagate Sedum sieboldii from leaves and not from cuttings?
If it works at all, does it work only with older leaves rather than fresh leaves?

That is a great question Paleo. Now I will have to experiment to see what works.
Meanwhile some one else might already have that information. Let's see who pops in with information.

I don't have the plant yet otherwise I would have tried, I was curious in case I get some bad plants how easy would it be to start them from zero. I just couldn't find so far the normal sieboldii which I like, I've seen only variegated variants for sale.

Tip cuttings work well.

If anyone else except valleylynn is willing to try to see if they can be propagated from leaf that would be cool, it seems there will be a while until I can find a non-variegated variant to buy, somewhere around me. I mean there is a source extra close but reviews tell of very bad quality on the sieboldii

Yes, better to stick with a supplier that has healthy plants.