NM respawn conditions,,,

Greetings, been making the sad sad attempt to complete the quest: An Imperial Heist
Specifically Killing the three NMs Mega Bosses and obtaining their titles to further progress in mythic wpn upgrades.
My suggestion is doing something about the respawn conditions regarding Besieged. Currently it reads if their camp is advancing and/or attacking the NM boss will not respawn for one hour after besieged is over. The problem I and I'm sure others may be experiencing is: "If they are defeated during besieged their respawn time is unknown."
In short my group somehow got lucky with Gulool Ja Ja and we obtained his title.
Attempted Medusa today and she was no where to be seen.
Have attempted Gurfurlur the Menacing "multiple" times with no success of his appearance...
Is there something you can do to remedy this? Perhaps have a set respawn time regardless of a besieged outcome.
Thank you and I hope you can help resolve this issue.