Border's web site does not indicate recommended longbow lengths for draw length ranges.
Send an email to Sid Sr and ask him.
Just understand that he is still backed up on emails from returning from holiday shop closure, so it might take a couple of days.
I hope that I have not over-stepped. But I am a big Border fan.
I have been messaging back and forth with Sid in regards to a set of CH limbs, so I asked him for you.
For the 64", his recommended draw length is up to 28".
Here is a link to the web site. www.borderbows.com/harrier-royale-gl-p554.html
If it were 5# lighter, or I was sure that my shoulder surgery will heal enough, it wouldn't be here.