ANSWER:
I have it figured out, as i'm new to flask and working with full stack I wasn't aware of this, but it seems you only use url_for to reference static outside of the static folder.
When inside the static folder you use the standard relational paths.
(instead of)
@font-face {
font-display: block;
font-family: "bootstrap-icons";
src: url("{{url_for('static', filename='/fonts/vendor/bootstrap/bootstrap-icons.woff2')}}") format("woff2"),
url("{{url_for('static', filename='/fonts/vendor/bootstrap/bootstrap-icons.woff')}}") format("woff");
}
(it's this)
@font-face {
font-display: block;
font-family: "bootstrap-icons";
src: url("../../../fonts/vendor/bootstrap/bootstrap-icons.woff2") format("woff2"),
url("../../../fonts/vendor/bootstrap/bootstrap-icons.woff") format("woff");
}
(not sure if i should delete this question but seeing as I couldn't find the answer on stack overflow will leave it up in case anyone runs into a similar issue)