Mine is far too young in the bottle to really tell, so i'm largely just referencing theory that i'm guessing you're already familiar with: the lower the temp, the more subtle the esters/phenolics. But that result varies enormously from strain to strain, so the theory doesn't provide a great guide for the ideal ferm temp schedule for this. Mine is definitely quite subtle on the aromatics, so i'd guess it might've been better to ferment mine a little higher. I'm also not 100% sure how these aromatics develop over time. I suspect these type of aromatics (Belgian esters, i believe) actually improve and shine more over time, as opposed to fading over time like other (Belgian) phenolics or hops oils/aromatics.
One other detail: even at 18°C, my WLP-530 was
juuuuuust pushing on the glad wrap, so filled ~8L headspace. For this, i was grateful i'd dropped it to 18°C.
I'd suggest to see if you can find any particular detail on the effect of high & low ferm temps on the ester profile of the WLP-530 (i assume you're using this?) as an added guide.
Failing that, i'd possibly go for ~21-22°C for the first day or 3 of active fermentation (partly depends on how fast it attenuates, so maybe ~25-40% chewed through), then let it rise a degree or so each day thereafter. Just a suggestion though