I turned off Vsync and exited the game and launcher and restarted my computer with both monitors connected and I no longer get the memory error, but when choosing a server and clicking 'more details', the background goes dim as usual and the pop up for the server mods does not appear. At that point the launcher is unable to do anything and I have to force close the launcher via Steam. The window may be popping up somewhere, but if it is, it is completely out of sight. This happens in both windowed and full screen modes.

I do not, but one is 3440x1440 (monitor) and the other is 3840x2160 (TV). Other than the resolution of the window surpassing the resolution of the ultrawide, since it might have crossed over into the other screen at some point, I also noticed that the config file has Vsync enabled. The 3840x2160 screen has Vsync and the 3440x1440 monitor has FreeSync, so I am unsure if this is causing the issue and will try disabling it when I get home and see if it works. I'm also curious to know if the settings of WinX and WinY are the reason I am getting the window for the server info and mods opening so wide I cannot see them fully until I make them smaller manually. Should I change this setting?
The config file has:
language="English";
adapter=-1;
3D_Performance=48387;
Resolution_Bpp=32;
Windowed=1;
WinX=-1158;
WinY=35;
WindowWidth=3840;
WindowHeight=2160;
MSAA=0;
PostFX=2;
VSync=1;
FXAO=1;
AToC=0;
AnisoFilter=4;
TerrainDetail=2;
FXAA=4;

It does, with both the windowed settings enabled in the steam settings as well as the Dayz launcher.

I gave that a shot and also added '-MaxMem=12000' to the launch script, but to no avail.