No export options when adding borders

Good morning.

The new "add border and share feature" is a brilliant idea to be able to output the photos directly to social media (mostly Instagram), but...it doesn't have ANY export options, so it's useless right now.

If you click on "add border and share", no export option appears:
You can't choose quality, color space, output sharpening...and most crucial of all, you can't choose the dimensions of the photograph.

Right now, if I choose a square frame (1:1), it makes me a 2108x2108px photo, a completely random number that cannot be changed. For Instagram, we are supposed to upload the images with a long side of 1080px (on some sites I have read that double would also work). The same happens with the rest of the social networks, or even for your own use. Each requires a different dimension.

Why don't we have output options when we add the border? Is there something I'm missing?

Thanks in advance,

Sergio