ANSWER:
There is nothing to confuse yourself with.
The question was about reciting the ayah as part of the athkar weather in the morning and evening or after fard prayers or before going to bed.
All those that was taught to us by the prophet salla Allahu alaihi wa sallam was never mentioned with seeking refuge in Allah from satan.
Therefore, if one wants to say it before ayatul kursi, this is permissible but one can’t say it is from the sunnah as it is part of the athkar and not part of reciting the Quran.