Isnt this, in part, covered under the Rehabilitation of offenders Act?
"Applying for Insurance
You may say that you do not have any previous convictions on an application form for an insurance policy as long as the rehabilitation period has ended and the convictions are spent. This still applies even if the convictions are relevant to the insurance policy being taken out – you do not have to disclose spent road traffic convictions when applying for car insurance, for example."
Now seeing as there is actually no conviction for any crime at all as you are offered the "course" instead of the conviction, providing certain criteria are met are the insurance companies now not running the high risk of getting their collective asses kicked again for discrimination, as there no way they can force an answer to the question and it is your right whether you chose to answer it or not?
Secondly what is a speed awareness course? .. the whole question is ambiguous. I may have attended a course for speed awareness as part of my employment [ say for example i work for drivetech], i may have attended one of a thousand advanced driver days and one of these may have related to speed and the the appropriate us of said speed...do the insurance companies expect me to answer "Yes" to this?