I've just finished a quilt using Invisafil 100 wt in the needle and in the bobbin. I quilt on a Juki TL2010Q, which I believe is very similar to rryder's PQ1500.
My cone, in a net holder from Superior Threads, was mounted on the vertical holder on top of the machine. I guided the thread into the middle hole of the "three-hole" guide, then threaded the usual way. I lowered top tension A LOT (almost to zero I would think). I tightened bobbin tension about 1/8 of a turn. I used a size 16 topstitch needle.
The above is the end result of a lot of trial and error scenarios. Success with the size 16 needle was a surprise. I had assumed that such fine thread would work better with a smaller needle. I had started out with my usual size 14 topstitch, so I changed to a size 12. The result was even more frequent thread fraying and breaking.
Once I got the right set-up, I did the whole quilt with not one thread fray or break.
Keep us posted, rryder.