Sounds like you got some good advice and may have made some beneficial adjustments.
I have a HHB selfbow here I made in '04 and checked its numbers. It's 64" ntn, 60# @ 28", and just 1 5/16" wide at the flares. Some might consider that narrow even for osage at those specs. Radiused belly. Not heat treated. Started off straight and now has an evenly dispersed 1 1/2" string follow but no frets after thousands of arrows. Maybe I should have reflexed it, or made it a bit wider and/or longer or heat treated it to ward off that string follow, but eh, whatever, I don't mind much. It's been a good bow... and still is.
I've made bamboo backed hophornbeam bows too. Never had one of them fret either. I trap all my boo backed bows. BBHHB are nice, narrow, petite, just the way I like em