Transfer switch/one generator

I will try to make a long story short. I have two EcoFlow Delta Pros that are tethered together and wired to a manual 6 circuit transfer switch that is utilizing 120 volts only.
One of the units is heading back for repairs so I will have only the one unit for who knows how long. My question is can I safely use the other unit alone with the transfer switch? If so will all six circuits be available? Will I need to use an RV plug and outlet?

It should work just fine.
But if you had it wired 240 split phase input, only half the circuits will operate.

Thanks, I believe with the tethering system from EcoFlow it was split in half, three circuits dedicated to one unit and three dedicated to the other, even though all circuits were handling 120 volts only. So I assume that if I use the same system with only one unit, only three circuits will be available.

This is the basic setup. I guess what I am wondering is if disconnect one unit can I still use the plug/outlet as is even though I will only have three circuits available on the transfer switch.

Most likely it will disable 3