A fragrance being stable, that is not accelerating or decelerating or discoloring (etc), depends on the formulation of the fragrance. While what a fragrance does really depends on the properties of the fragrance, there are some tweaks to a recipe one can make in anticipation of a fragrance that is known to "misbehave"
For example, I use exclusively EOs, but even some of those misbehave. Ginger and clove EOs accelerate trace due to the amount of the compound eugenol they contain. When I want to use one of these I use my slow moving recipe, which has more liquid oil than hard oils. My ratio depends on the size of the batch, but generally I use 60-70% liquid oil to 30-40% hard oils when I want to use those EOs. Caution here - not all liquid oils are created equal. When I say "liquid oils" I'm referring to "Basic" Olive (not pomace) or Canola. Hope that helps!
I see you just posted something... I haven't noticed any benefit to adding my EOs to my oil vs into my batter, but perhaps FOs are different. I will say this - take a good look at the properties/notes and reviews of that FO. Perhaps even send an email to the supplier. Find out if it's Double check if it's known to accelerate trace as well as the usage rate and what they recommend as the best method of use, including when it's best to add it when making soap.
ETA: Just in case...I've found that Rice Bran Oil and Castor oils tend to speed up trace. This is different than "accelerate" trace. I now use these liquid oils in my fast moving recipe when I just want to make family bars and move on.