I think you will find that Co's in general will allow for non compliance of COBT as the ramifications of scheduling goes out the window awaiting another COBT which could be Christ knows how long! Trouble is going non compliant means ATC can slow you down, hold you & generally dick you around 'till the cows come home & under normal Ops when you plan for std fuel as per the flight plan with an original COBT that can no longer be met when yr sitting in yr cockpit all means yr stuffed either way as you won't have the extra res to hold etc by going non compliant. Catch 22 situation.
We all know that COBT or any GDP is useless, too many variables & rarely works.
Wmk2