Hi Bill,
Looking through the code I found only one place where EnableSSLInChildSites is actually used, I'm going to remove that setting as it has been replaced with different logic a while back.
In the current logic
<add key="SSLIsAvailable" value="true" />
is global for all sites, to make only a single site use SSL set that to false and add this:
<add key="Site1-SSLIsAvailable" value="true" />
where 1 is the SiteID for the site that should have SSL
This gives more granular control over which sites can use SSL
Hope that helps,
Joe