So my text is in UI mode so for the Rect Transform to be aligned to the pixel grid it only needs to be a number with no decimals since the canvas is already at 640x360, which it is, and i tried what you said about sizes, but I think that's also for 3D text, cause it made my text tiny in my Canvas.
I think my issue is that middle anchor center alignment is not working depending on the amount of pixels.
In this following example, its the same text box, with two lines of text, one with an uneven amount of pixels, and the other with an even amount of pixels, and you can see how one is aligned and the other one is not. So I'm wondering if I can make it have a "middle rounded" anchor in a way, that's rounded to the nearest pixel, therefore pixel perfect aligning both lines.
