Thought I would update this thread. Most of the pots I moved into Seramis are doing well and seem none the worse.
Fritillaria acmopetala. Although nothing was showing above ground when I moved them, most of this pot had produced quite large roots.
F. olivieri. After coming across the acmopetala I was more careful, scraping away the compost for as far as possible just below the seed layer, then placing this on top of the pot. The scattering of Seramis is to tell me that these have been repotted in this way. These all appeared above ground within the space of a few days.
Some, such as this
F. gussichiae, seemed too far advanced to risk repotting.
These
F. argolica were a bit bigger again and I thought would be ok, but seem to have suffered from fungal attack - perhaps due to damage / stress when transplanting or maybe they would have had it anyway.
There were also a few 'foundlings' - seeds which dropped out onto the potting bench and which I found germinating later. I have heeled them into the plunge to give them a chance.