Yeah if you notice I used the delta_time or w/e constant to calculate my scrolling background.
There are many ways to do your own scrolling but majority of people will use traditional methods - When I modified your demo, it looked 1:1 identical yet did not have the gaps anymore.
Anyway, no I said I don't wtf to your code you sent me in a PM because your rounding was mixed with earlier suggestions we made for vertices, not the projection coordinates. Thus my wtf response.
I did try the proper rounding method before but I used X+ instead of x =, so now it all works. I just finished testing this with DX9, window and full screen and it worked too.
I removed the +0.25 thing that was there, I checked before and after and fonts looked identical, and replaced it with the rounding fix. So now OpenGL1, OpenGL3 and DX9 are patched with this fix.
Anyway, wonderful, good thing it works, and yeah I'm certain nobody would ever have a need for a camera at a half pixel would they? When the camera is at half-pixels all you ever notice are artifacts, it looks the same as if it were at the rounded coordinate except shittier.
Exactly, I mean those are little details, what matters is the game, and visually the majority of people playing the games will not dissect the pixel placement on the screen. With all the movement and concentrating on the game those are details

So am I correct in my assumptions or does someone have evidence to the contrary?
Actually your assumption is logic.
We established at 0.01 works for us all,
and you've guided me to discovering that whenever user x/y + engine offsets = an integer, that the artifacts appear again, and yes half a pixel looks uglier than rounded to the nearest, after looking closely did not see .01 adding any visual effects to the fonts, I mean most people don't care or don't have trained eyes, and besides when playing at your monitor's native resolution 1:1 with your game res, it is never an issue. Most of the blurriness or other spacing/thickness inconsistencies will be seen due to monitor upscaling and game scaling, as a lot of people use room sizes < than their monitor res anyway.