@sylvester because this depends on the pi firmware. I don't think 4.0 has the right firmware to set it to 240p, but 4.0.1 has it

@chubsta maybe you could use an external usb stick to store your data. With this you can syncronize your sd card with a usb stick of your choice and another advantage is that you have the system separated from your data 🙂

https://github.com/recalbox/recalbox-os/wiki/Use-an-external-usb-storage-device-on-recalbox-(EN)