Mozilla Firefox: Repositions/Resizes its window at some point during load. When? (Win 10)

If you have no extensions installed in Firefox or no other plug-in that may increase Firefox's load time, you probably will not notice this. However, with my approximately two-dozen extensions, there's significant load time — at least relative to loading with none.

I have an AHK script that includes a window resizer. Depending on the class/exe/title/etc. of the window that opens, it will get resized or moved around the desktop. With every other window that I have this script acting on, the move/sizing "sticks" — and the window keeps that size and position. However, with a significant number of extensions installed, Firefox will resize itself and/or move itself after my script has resized its window.

The significant item in my case, I believe, is that I size certain windows in Windows 10 just off the screen — on the left and bottom boundaries. Windows 10 resizer handles are thick and clear. Any motion on a window undeeath (such as Outlook checking the mail server or an ad animation in another program) can distract me thinking it's an alert or whatever. (Yes, I am that squirrely.) Because my screen real estate is too large to just take up completely with a browser window, I have these windows in the "restored" state. Maximizing, of course, takes the client portion of the window to the edges of the screen. In a restored state, however, the resizer handles come into play. The total width of the restored window now includes the resizer handles.

I believe that, at some point during the loading process, Firefox realizes that its window is partially hidden and helps me out by moving the window back completely on-screen. I don't believe it's a Windows action because none of the other windows are affected.

tl;dr version: Firefox auto-moves any off-screen part of its window back into viewable area. I don't need that because I do it myself.

Can anyone help me out with a setting in about:config or some other setting that can disable this check?

Recent Questions...