And - regarding the more cylindrical /3 sided growths in your clump - many old Epiphyllum hybrids like to revert to the Disocactus parent.
When you get ready to start your own plant/pot, I would ask for a few cuttings ( of the flat growth) and pot them together. They will make a nice basket in a season. A single cutting will take "forever"!!
Also, if you look at the tips of the flat growths, many have small roots starting. If you plant a few of those with those tips into the soil/upside down, they will root easily! ( You might see this in old greenhouses focussing on Epiphyllums. Tips root in neighboring pot.)
I find they actually root easier for me that way. Less chance of rot.
