Possible to use SideCar with MacBook Pro w/ 4 external displays?

As noted in the tech specs of the MacBook Pro (16-inch, 2019), it can support to four external 4k monitors, and that's how I've set up mine. The maxed-out number of monitors + the laptop's display effectively give me five displays.

Can I use SideCar to add an additional display to this set-up?

MacBook Pro + SIdeCar + 4 external displays = 6 displays

Or would SideCar count as one of the 4 external displays?

MacBook Pro + SideCar + 3 external displays = 5 displays

I don't currently have a compatible iPad to test this with and I can't seem to find the answer anywhere else.