Hmmm….. I’m not exactly sure how comparable these two exams are…? Are you wanting to take it so that you can practice test taking? or is it to practice content?
I was not in Kenya for secondary school, so I never took KCSE, but based on a quick search I see it seems to be very comprehensive involving not only English and Math, but other subjects like Geography, CRE, Home-Science, and Languages. In contrast, the SAT exam only has writing, critical reading and mathematics (all in English)
So: taking it would help you practice writing, answering multiple choice reading questions, and standardized math under a fixed time block…. does the KCSE have those sections? If so, then it might be a refresher… if not, then I don’t think sitting for the SAT would be helpful….
I will have to defer to my colleagues for a more conclusive answer!