Is it possible to do a 2-category sort? i.e. alphabetically by planet name then alphabetically by natural id. for example:
.
.
.
Gasworld
Prism
Proxion
Saladin
DW-739a
RC-040a
TO-442a
YI-715a
.
.
.
That would solve the issue and also be easier to read through than a list that goes back and forth between named and unnamed planets.
Regardless, any sorting method (even if it is not alphabetical) will be an improvement if it means the list will be in the same order every time.