Danger of recovery mode on the GL-MT6000

I read on a thread I can't locate that trying to enter recovery mode requires you to be connected to one of the ports and if you are connected to a different port, it won't enter recovery mode correctly. Is this still true and do I remember this right?

https://openwrt.org/toh/gl.inet/gl-mt6000#oem_recovery

Yes, all other ports must be disconnected. Including wan and USB.