The fact is that after Oct 31st all new, or extension of stay applications require you to have insurance from their 'authorised' companies,
I got my last extension on Aug 5th in Samui, I'm guessing when I do a 90 day report, I will be told if it now applies to me, but for definite, it will apply for next extension.
*(I went back to UK for a holiday, so on the 27th it will be my first 90 check in).
The IO's are a kind of law to themselves. In Samui, they didn't want to do the combination method for mine in August, told me if I put the money in, time didn't matter even though I was three weeks away from renewal.