All external instrument tracks frozen but still realtime audio export required

After freezing all external instrument tracks and re-opening the project the audio mixdown still prompts ’ real-time export is needed’. Cubase 12 Pro. This bug has been around for a very long time now at least since C9. This is of course very much not what anyone with external gear wants and in my case it’s an absolute workflow killer. Realtime exports are quite frankly a nightmare. Yes there are all kinds of messy workarounds one can think of but this is simply a matter of a single binary flag to be correctly saved in the .cpr project file. A nasty bug imho, kindly fix with priority - many thanks.