ellivort, Main reason for people to make Cfs with notice is because every one want to have relative fair chances to prepare for incoming conflict. When you send notice to another kingdom during his post war time you effective cut time they have for prepare. Post war is for recover from war, you didunt had any war so you have noting to recover. Notice from 3 days is for both kingdoms have his time to prepare for incoming fight. When you send notice during post war you effective drop time what have your opponent and its unfair. Its why i call it lame/cheap play. If its don't break your deal terms its legit but still very unethical and its bring only problems in long turn.
Here is second very important moment too. Conflict from war looked unsolved and chances for b2b war was very high. Now your notice force Sleepy to look for CF. So your actions had direct affect in this conflict too. Its very unfair and lame.
Im not Shai fan. He did to kingdom i was in past something similar to what you are doing now. I still didn't forget or forgive him/binar for it. This kind play really make long turn enemy. My advice is don't play like it.