Duromax MX4500E Generator manual perplexing

[Moving Along]

I have the adapter to connect the generator to my 50 amp power cable. It just perplexes me the way the manual says to use the 120/240v socket.
It says:

"VOLTAGE SELECTOR SWITCH (MX4500/MX4500E)
The voltage selector switches the main power carrying windings of the generator to produce
"120V ONLY" or "120/240V". If a 240V appliance is connected to the 4-prong receptacle, the
switch must be in the "120/240V" position. If only a 120V appliance is being connected to any
of the 120V 3-prong receptacles, select the "120V ONLY" position.
* 120/240V: The 120V and 120/240V receptacles can be used simultaneously.
* 120V: ONLY the 120V receptacles can be used. Do not use the 120/240V receptacle in this position. Rated power will be available at the 120V twist lock receptacle."

Go figure. If you are only needing 120v you keep it in the 120v only position and "only the 120v 3prong sockets can be used." However, it goes on to say "rated power will be available at the 120v twist lock receptacle."

Well the only twist lock receptacle is the 120/240v receptacle. The one you are not supposed to use in 120v mode? Huh?

Can someone answer this? Is it safe to use my twist lock adaptor/50 amp plug dog bone to power my fifth wheel, which contains no appliances over 120v while the generator in the 120v/240v mode? Thanks