Very helpful! May not save a ton of time, but as someone who performs this action 100 times per day, every little bit helps.

My personal plug for my Github WYSIWYG wishlist item: create an easy way to make images smaller (not full width). Everyone on our team gripes about the fact that, when posting screenshots (common in code review threads), they immediately bump up to full width, making portrait images look massive.

The only way to get around this is to paste the image, wait until it uploads, then replace the Markdown image tag ([text](url)) with <img src="url" width="400" />, which is incredibly annoying to do 15 times per day.