Uberwaltz, you measure it! Check out this
https://www.parts-express.com/dayton-audio-omnimic-v2-acoustic-measurement-system--390-792. My room control system essentially does the same thing. It measures each individual speaker. The frequency response above 10 kHz is significantly different in my right ESL than in the Left one. The only difference is the right one has a window in front of it on the side wall. The system corrected it but beforehand the window was smearing the image.
To produce the best image the frequency response of both speakers has to be identical or the image will smear to the side that is louder at any given frequency. There are always differences from one speaker to another of the same type not to mention that the speakers occupy different positions in the room. If you measure your system you will be amazed if not terrified at the variations in frequency response particularly below 100 Hz. The curve will look like a profile of the alps.
It is a lot of fun to measure other people's system and show them how bad things are.
So, Uberwaltz, do not downplay those windows. More than likely they are having a significant effect on the sound. But, it is hard to predict how. If you want to know measure it. But if you are not planning to get a room control unit don't bother. Ignorance is bliss.