These plants are now flowering. Germination was a bit patchy, but the resulting plants are spectacular - I've measured them at over 8 feet high.
I've also been collecting from a 50 plant original Kral growout. This has been progressively ripening for about the last 5 months, so I'm not sure of the quality. I've been drying it down in batches as I harvest it, and storing it in the freezer, so I will need to work up a bed to sow this soon for another autumn growout, and to assess it for quality.
The rest of the Kral F1 seed was sown about a month ago under heavy undefelt mulch at my second garden, but nothing has germinated, so it looks like it wasn't viable, or the stinking hot 43 degree days have sent it dormant.