Q.Could You Amend Your Planting Instructions For Aztec Lilies?
In the narrative, you recommend planting the bulbs neck exposed and then suggest planting them 4″ deep. Which is it?

Certified GKH Gardening Expert
These two publications say the same thing. Although the bulb has a somewhat long neck, the plump part of the bulb should be planted 3 to 4 inches deep. I think it is less important that the top of the bulb be above soil, because that was not a common instruction.
https://hort.extension.wisc.edu/articles/aztec-lily-sprekelia-formosissima/
https://www.ocregister.com/2017/12/11/master-gardener-how-to-grow-aztec-lillies/