I use a variant of the Cloake system. For larvae, I use the Nicot system. I have had lots of success.
My last batch of queens failed and I'm not sure why.
I checked the cells on day 6 (counting from egg), which is one day after the Cloake re-unite. The cells were about 50% drawn.
When I pulled them at day 15 the cell bars were heavily burr combed. So much so that I couldn't be sure there were queens in there. But I carefully cut them apart and installed in nucs.
On day 19 I checked and all cells were dead. The queen larvae was present but dead. A few were in the grub stage but most seemed to be in the pupae stage.
What went wrong? I'm wondering if when I checked them on day six I may have chilled the larvae. But I'm not sure that makes sense because they advanced to the pupae stage before dying. If I chilled them, seems like they would have died right away.