Just a little update.

Based on Justin's feedback. I have already worked out on a server-side block to insert forms in Gutenberg post/page that are created via the custom "Forms" screen.
https://share.getcloudapp.com/p9uPwgEx

So now it won't be a shortcode approach anymore for Gutenberg users. You can still use the shortcode to place the form anywhere outside Gutenberg.

This will be available in the next update soon. Following up on other feedback as well. 😇