I watched an episode of fifth gear
https://youtu.be/GL9-i9tcESU and the guy put diesel in a petrol car and petrol in a diesel car to see what happens. In both cases they ran for quite a long time. So even 100% works (with possible damage) so I'm not buying that there is a maximum mixture. Where did you get this data anyway?
The question still has not been answered: has anyone tried it?
https://youtu.be/pCr6bjQMrgU