Supine wrist stretch

Have been chugging along on Foundations for a few months now and am finally feeling like I'm stretching my limits. Pretty much every question I've had up until this point was already asked and answered here by somebody, but I haven't seen this one so here goes.

In doing the wrist stretches on Weighted Mobility, my hands simply will not face straight out when doing the supine wrist stretch (palms up, hands forward). I have to get my elbows quite bent to even get my hands pointing directly away from my body. As it stands, the hands point inward towards the middle. Is this something I should be working to improve, and if so how?

I asked in the beginning about wrists due to working mostly at a desk all day and was recommended to do the Handstand course. My wrists are in way better shape than they were in the beginning, but this particular thing hasn't really improved.

HI Doug, can you post a video of your execution, please?

Here's a picture for now- hopefully this gives you an idea. I guess I have to use YouTube to post video?

This is probably due to the pronator muscles, much more involved during desk and mouse and keyboard work. you can easily stretch them if you perform a shoulder dislocate with medium/large grip and no weight and you try to hold the bar with all the fingers.