There are apparently different ways of doing this. I hardly do any planning on my computer. I generate a huge gpx file for a large area and use this on my phone for a week or two. All planning is done on my phone.

Perhaps it is much, but still it is solved nice and simple in other apps

I don't know what others normally do, but I never take my PC with me and generate pocket queries out in the field. That is too much trouble for me.