Solar install charge question

My controller "plays well" with all other charging devices.

"I have read that the converter IQ charger and the Solar Charge controller can confuse each other..."

BFL is correct. You are overthinking this issue. You'll love solar. Your solar controller will probably be smarter than your converter.

Agree with above, they can both charge, and the higher voltage source will be in charge of the charge.

Which charger is smarter? You can easily just flip the breaker to the RV electric charger when you have good sun, and plugged in, so only the solar is doing the work, no need to add extra switches. The charger usually is on its own circuit breaker, not shared with anything.
However, this means you are running of batteries and not the DC power from the converter. Using the converter will prolong the battery life. Better to have a switch from converter to battery and is same reason as explained below... safety.
Again, you do not need a switch, but for maintenance is good idea.

Since you are doing the install I recommend putting a switch on the positive feed from the panel(s) so you can turn them off. Before disconnecting the battery for any maintenance reason you should first disconnect the solar panel to prevent any possibility of damage to the panel.
I used a single circuit breaker switch so it doubles as a fuse/breaker and a manual switch.

Are you running parallel or in series?

Overthinking is correct.

The one with the higher voltage will do most of the charging at the time. No confusion. The converter only works when you have shore power or on gen, and you don't care if the solar does anything then, so no worries. The solar is for when off grid so no converter then anyway.