The frames in PL have very limited adjustmenst. It is not possible to:
Have a diffrent thickness invertical or horizontal frame
Have more than 200px width: with high deffinition sensors it is not so much
With a inner line: it is not possible to specify the width of this line.
To get “artistics” frame it should be suitable to add some manual adjustments to fit with the user wish.
I would really support this. Having a slightly thinner plain white frame would make a major difference. The overly thick frames detract from the photo rather than enhance it as other software allows one to add a thinner frame.