Hi and welcome,
Manually added plates are fine, in reality, but they are a bit of extra messing around to place.
I'm not actually sure which part you are wanting to turn off in your question, do you mean hide the beams?
If you don't want to do manually placed plates, try the "assemblies" tool Under the "structure" tab.

You will need to set the rules for the connection, (ie moment etc.) and some other rules but they are straight forward and revit will place automatically for you the connection, and modify it automatically if the rules happen to change also.

Having said that, I am not 100% sure it will do a flange plate in this manner for you but Worth checking out at least, and assemblies will save you time in general.

end plate

I got it sorted with revit 2018 but thankyou for replying ;-)