Off topic - do you have this graph/data that you could share publicly?
This is something that I’d been thinking about earlier this year.. I was suspicious that when you were in a little gear up front in erg mode that force would be applied equally throughout the pedal stroke (function of angle versus applied force would be constant), rather than variable like actually on the bike. And that this may be part of the reason why indoor FTP is lower in many people. And why using the small ring in erg mode is more difficult. However I couldn’t find any actual data on this.
If you have data that suggests that the standard deviation of power as a function of angle is much lower in the small chain ring than the big chain ring even in erg mode, this would prove that pedalling in erg mode (at least in certain gearings) is fundamentally different physiologically than on-bike, and would explain a lot of things.