Thanks! Haven't tried that yet, should work. Haven't used that overload before.
Suggestion for the manual, add a small note in the topic 'Sorting' about sorting related collections, it should point to this prefetch path sorting functionality which is indeed mentioned in the manual but I was looking in the wrong place.
Even beter, a few examples in the sorter topic about how to use a sort expression.
When using it to fetch a collection ..
When using it to fetch a related collection ..
etc ..
I simply can't remember all the functionality / overloads this tool provides, the manual is the first place I look for answers.