Have you called and spoken to them? I did a quote last year for Gill's Beemer and they (Admiral) specifically asked about speed awareness courses. It was the reason I didn't renew with them the following year. The quote went up by about £40 as well which was a tad annoying, although it's to be expected.
Just because it doesn't ask on the comparison website (or directly on the insurers website), doesn't mean it isn't in their small print... probably worth checking. It's unlikely to ever come out unless you had a serious accident, but as other's have said, you would have breached your insurance policy and lied to get insurance... not something you want to declare in later years when trying to get insurance as they generally take a much harsher view on people who've committed fraud over someone who's been on a naughty buy/girl course!
+1^^^