Hey Gazoo! Wanted to offer some words of encouragement. I DO think your lighting schedule/Cat schedule will work for you with practice--for me, it takes a round or two to dial the CAT in for the strain I'm growing to get the effects I'm looking for.
I encourage folks to try not to get too caught up in 'perfect timing'. For me, part of the fun is getting to play with when to drench for each strain, and not keeping things on an uber-strict schedule. 'Late' (I dislike that term) CAT drenches tend to leave more of the 'funky' terps (that's how I'd describe them, at least!) behind. This can make all the difference between "That looks like some good weed", and, "HOLY HELL, you grew this!? Hey guys, check this out!"
For me, growing strains like UK Cheese, Sour Diesel, even some OG Phenos--I prefer a CAT drench a little 'later' than others might use it. The pungent terps really start singing then!
Really, it's just one more tool in the 'kit' we get to play with in our quest to grow the best possible cannabis. Playing with the CAT Drench we get the ability to essentially customize terpene expression--and therefore effects--of the cannabis we grow. "Late" is just a label--I (occasionally) wear it with pride.
Cheers gang, hope everyone's hump day is off to a good start.
-Stoney