My father builds custom string sets for wheelie bows that surpass anything I've ever seen sold. He IMO has perfected the art. He has become quite well known for his strings statewide and beyond.
I've stolen some of his hard learned string building secrets (I'm his son so I can do that) and applied it to the Flemish string. As stated already the tinsile strength of D-97 is incredible. Here's what I've been doing:
I've been building 6 strand strings for 50-60# bows with absolutely zero issues. Twist/build your string as you normally would. Then prestress the string. By this I mean ( I built a jig to do this) put the loops over each end of the jig and start cinching her down. As I turn the wrench and the string begins to tighten you can actually see and sometimes hear each strand "seat" itself in the loop ends and entire length of the string. I take my strings to around 300# and let them sit for about an hour.
I then check for what I want my finished length to be and twist accordingly. At this point I "burnish" the string. For those not familiar, simply take a piece of nylon string, wrap it around your new string once starting in the center. Grabbing both ends of the nylon string with enough pressure to keep your wrap tight, drag it to one loop and then to the other. Do this 2 to 3 times. Keep in mind your string is still at 300# of pressure. What this does is seat any remaining fibers and gives you a perfectly round string. You will be generating some heat while doing this so don't go over board or you will start to lift fibers.
Check your length one more time (it should not have stretched much if any at this point). Serve it up to fit the diameter you desire and your set. Combine Halo serving and a bigshot glove with nylon fingers or a quality tab and I don't think you'll find a smoother, slicker release.
Put the string one your bow and it will never move again. You can still add twist or take them out (a few) to get your desired brace height. Remember this string saw 300# for a good while and will never see it again while on your bow.
Ok I got really long winded on this but saw you guys talking about skinny strings and thought I'd throw this out there for you.
Oh almost forgot, on my 6 strand strings I pad my loops to 8-10 strands for abrasion resistance.
If you made it through it thanks for reading!