When can future employer file/extend H1B base on approved I140?

As far as I know, H1B extensions based on approved I-140 can only be filed no earlier than 6 months prior to the H1B (6 year) expiration. But what if I want to change my job 10 months before the H1B expiration - Can the new/future employer directly file and extend my H1B based on my approved I-140 (while I’m still working at my current company), even if it’s BEFORE 6 months prior to the H1B expiration? When is the earliest time that the new employer can start filing H1B extension for me? Thank you!

The rule you mentioned is only when the same employer wants to apply for extension.

If a new employer comes into picture, then it can be filed anytime when the new employment starts. So this can be done even when 2+ years are still left on the original petition.

thank you very much Saurabh!