Hi Steff
No, it’s related to model IMPORT and if you have there the MTL file and texture file, it will USE the texture size from the already present file.
So if you want to use your OWN texture ( custom UVs done ), you need to delete *.MTL which is related to the OBJ.
Do you think this behavior can be used or it’s SAFER to skip this ( as ZBrush and some other software export even empty texture on export with 1-4k texture size )?