I have a garden bed of sempervivums that are flowering and will of course die when they’re done. I can see the seeds on some of them that are further along in their process, and I’m wondering if theres a best way to harvest them to propagate new plants?

Should I just leave them to drop their seeds in the garden bed? Or should I cut the stems and germinate the seeds inside under controlled conditions? I’m planning on letting them fill in to a full mat of hens and chicks in the garden beds and trying to speed up the process however I can.