If we do that, then we can't import it via @import in twig because it will be...

If we do that, then we can't import it via @import in twig because it will be outside of the templates folder

We can use include to add the SVG image. We're already doing it in different places in the Olivero theme. {% include "@olivero/../images/site-under-maintenance-icon.svg" %}

Check Olivero maintenance page template here