Far be it for me to offer any suggestions but instead of 'zap-a-gap' which is nothing more than Thick CA which will dry hard and stiff. I use a lot of CA from Thin, Medium and Thick.
Will that create a new stress point below where the CA ends on the leader and the threads can still fray?
How about something like Flexment or Shoe-Goo so there's more give and flexing at the tip ring but impedes fraying?