I’m late to this discussion, but I have had the tag end of an arbor knot (slip knot) in both fluoro (and I believe nylon) slip. So I begin the arbor knot with two figure 8 or overhand knots as a “handle” knot and a “stopper” knot spaced about 1/2" or 13mm apart at the end of the line.
Then I tie the arbor knot slightly below the two figure 8s.
I then stick two fingers into the slip knot loop and pull on the standing end of the line to seat the stopper knot against the slip knot.
This produces a slip loop knot with a tag that will never slip, and ( @Kris.Franqui 
) makes it a little easier to manipulate the slip knot to attach to and remove from the lillian that can help with cold hands.