How godot squeezes SVG when processing?
SVG is rasterized to an image using NanoSVG when importing, so it is not a "true" vector when used in-game. Also, keep in mind NanoSVG is quite limited in terms of supported features: some complex vectors won't render correctly (or at all).
And is it rational to use SVG, or better immediately PNG.
If you want control over the rendering process, I'd advise rendering SVGs to PNGs beforehand. This can be automated using Inkscape's command line interface.