Not using https automatically does not mean you cannot use https
I wasn't implying otherwise.
Indeed make the first request unencrypted. You will probably not even notice that happens, and you will think that encryption was used all the time.
Okay think about it this way:
Scenario 1: You do not have HTTPS Everywhere or KB SSL Enforcer but you do manually set websites to HTTPS when you visit them, the issue of first making unencrypted requests is there.
Scenario 2: You do have HTTPS Everywhere but not KB SSL Enforcer and you
do manually set websites to HTTPS when you visit them, the websites known by HTTPS Everywhere will not make any unencrypted requests but websites not known by HTTPS (or HSTS) will still have the issue of first requesting unencrypted.
Scenario 2.5: You do have HTTPS Everywhere but not KB SSL Enforcer and you
don't manually set websites to HTTPS when you visit them, websites known to HTTPS Everywhere will always be encrypted with no "leakage" however sites not known to HTTPS Everywhere will most likely always be HTTP instead of HTTPS which is more damaging than if just a single first requests were unencrypted.
Scenario 3: You do have KB SSL Enforcer but not HTTPS Everywhere, you have the issue of initial unencrypted request.
Scenario 4: You do have an extension like HTTPS Everywhere and KB SSL Enforcer combined, The sites known to support HTTPS would directly connect to that while sites not known would automatically test if HTTPS is supported, the issue of initial unencrypted requests is still there but you won't forget to change the site to HTTPS in either way and anything subsequent will always be via HTTPS if the site allows it.
So by merging them into one, in my opinion you don't really get anything negative, however you do the get positive thing of never forgetting to set the websites that support it to HTTPS.