It actually choses between different points depending from which direction I would come in.
Example: coming in from EDDB (which is roughly east of EHAM) will give me DOBAK, coming from EDDH (roughly NE) will also give me DOBAK. BUT: coming from EKKA (which is roughly NNE) will in fact give me TEMLU which perfectly makes sense considering the general calculated routes. If you turn on the “airspace” filter it will make even more sense to put you to that specific point.
If I’m not wrong this is a matter of regulations (e. g. AIRACs).
However, I might have found a way you could probably chose a different transition while on the world map: just enter departure and arrival airport (IFR), delete any fix that is between your last regular fix and the destination airport.
Go from there adding all the fixes from the desired STAR and select a fitting approach from there.
I just tested it and manually entered the fixes for EEL1A via SOMPO. The sim suggests an automatic approach to 18R which makes sense since current METAR shows winds from the south. I selected ILS 18R-N which resulted in a reasonable looking approach pattern.
Not sure how this might mess up ATC and things like that since you’d likely not enter via SOMPO when coming from the east but at least it looks like it’s possible to plan it that way.
Cheers.