How to build a Svele-Component without shadow-DOM?

There are a lot of discussions on GitHub

• 1748 (2018)
• 4073 (PR / 2019)
• 2516 (2019 / with Comment from Rich Harris, but he also had no clear answer)

Until Svelte-4 i could solve this with chriswards npm-package svelte-tag. But, Since Svelte-5 changed a lot this way is not working anymore.

On this post Hjorthhansen concluded «Ultimately, shadow DOM is not a requirement in order to build Web Components.»

Is it really true that there is no way to build Svelte as a custom element without Shadow DOM?

In my case, I work on Rails, with Vite as the front-end engine. Overall, I want to work the Rails way, but have the ability to build some special elements with Svelte. But if styles cannot be applied there, it makes no sense.