How to convince Remmina in a three monitor setup

I have two external monitors (both 1920x1200) connected to a laptop. I'm connecting to a Win10 (with also two monitors on its PC) via Remmina, with an *.rdp file supplied by Citrix Netscaler Gateway.

Every application that's maximized in the session takes all the space of both the displays. That's bad.

1. Can I convince Remmina to consider the two monitor setup on the remote system so that maximizing inside the session just uses one of the local displays?

2. If 1. isn't possible natively I have another idea:
   Can I connect with two sessions, one using the first remote display and one using the second?

What also makes me wonder is that there is a Multi monitor button in Remmina's session toolbar. But it only scrambles my displays when switching between fullscreen and a "non-fullscreen" mode (it's not restored/windowed mode, at least visually, since the title bar is missing for whatever reason).

Additional information (for potential future seekers, readers, attempters)

At first I struggled to convince Remmina to take all space of both the external monitors for the session (including/overlapping the space of the local bottom panel). I managed this via:

1. A Window Rule

   Created via Right-click Remmina's title bar➔More Actions➔Configure Special Window Settings.

2. Session toolbar

   • Toggle fullscreen mode (Right-Ctrl+F)
   • Toggle dynamic resolution update