WL_RELEASE has a customized cooldown of 1 second on iRO. It came about from it being possible to skip casting WL_READING_SB prior to WL_RELEASE via packet injection and was added around 2013 due to exploitation in PVP/WoE.
1) Major changes have been made to WL_READING_SB since then and reading books via packet injection hasn't been possible for many years
2) Even with the cooldown removed endgame/PVP players have little if any incentive to use WL_RELEASE
Given these two points, the cooldown is completely pointless and only hurts new players, and should be updated to match other official servers.
Cooldown information obtained from replay analyzer,
iRO:
HEADER_ZC_SKILL_POSTDELAY { "Skid": 2230, "Delaytm": 1000 }
kRO & thRO:
HEADER_ZC_SKILL_POSTDELAY is not present after casting Release