If BotD is off-cooldown and ready to go AND you won't get fucked by mechanics if you pop it (for example popping it less than 15-20s or so before a jump in A1S is bad) my intuition always tells me to pop GSK on cooldown until your BotD drops off before you re-up it before your next third hit.

The stat weights are in the first few posts:
DET - 0.139
CRIT - 0.162
SS - 0.104

ACC+SS until cap, CRIT before DET.