It doesn't appear to be implemented as a user visible proxy, it modifies the network stack. From:

https://twitter.com/matthew_d_green/status/56843703790644428...

Probably not a proxy; probably low-level socket interception in Windows.

So there isn't much the browsers can do to help the user.

At least the technical side of Lenovo's response is all the way to "We are writing a program to remove the certificates", which is probably the thing that is going to impact the most people.