Hot knife

[Tedder]

I have been making some Dyneema soft shackles out of 3mm Robline. John Franta recommends leaving the tails long after the crown knot if I cannot tighten them with working load pull--Colligo has a machine, I just have a block and tackle.
So, how should I finish these ends? I sailor-whipped one and it just doesn't look right.
Should I cut the line ends with a hot knife (that I don't have and would have to purchase for maybe only this purpose as I whip my other jobs) or just leave them ragged?