Hot reloading takes a lot of time

[SaadBazaz]

When developing using this library, hot reloads take a lot of time.

This occurs not only in the demo in this repo, but also happens in external projects using this library as an installed package.

I have a hunch it's because of Lit, or because of getSlotProp.

[SaadBazaz]

Possible reason?
lit/lit#1844

[SaadBazaz]

We're using this library in a professional project.

It's done well for us so far, but the biggest problem (out of many) is that hot-reloading in NextJS stops working when we use our library. Also, consequently I think, builds take too long.

We are considering revamping all our project's interface due to this. It's a huge issue.

If someone could fix this for us, that'd be awesome.

Hint:
I feel like it's got something to do with our usage of shadow DOMs. Maybe if we don't use Shadow DOMs, it might bring back this functionality (along with many others).

We've set up a bounty of 17.5 USD (negotiable) if someone from the community takes it up and delivers.