Today I tried a free online vector graphics editor called Vectr (vectr.com) and I found really interesting the way to round up the corners and then edit the corner radius.
The explanation in this animated gif: http://bit.ly/2lKMwbH and in this video https://youtu.be/9oxdrgA4JqE
Could be one method to apply to the highdesign for editing corners hatches?
Martin