I usually fall back to Illustrator and then clean up the resulting markup, or a text-based editor such as https://www.svgviewer.dev/
Your UX is quite polished, and your tool already supports more features than other ones I've found, good work!
For reference this is my project, https://github.com/jwmcglynn/donner, which has a web-based "editor" (currently just code-based editing) prototype here: https://jwmcglynn.github.io/donner-editor/
SVG is one of those things that has lots of potential but has been impacted by not-so-great tooling, it's my passion and I'm glad to see innovation in the space.