In reply to MaAnna.

What we're trying to do is to provide our customers with a "single-click" solution to enable, configure and force the https usage on a WordPress website. I don't see us forcing https on all customers any time soon to be honest because as you said, that would affect a lot of different scripts. I think that would happen natually in the course of time, especially when certain features in WordPress become available only for sites with SSL configured.

As to your security concerns, if a firewall relies on http requests, it's simply not a good firewall and I would look for an alternative. Besides, we wouldn't do such change without informing our customers beforehand.