Need a rich text snippet tool

I have a block of text that is used on multiple posts and would like to edit this centrally instead of having to go into each post.

I’ve tried various snippet plugins but none so far have covered the two requirements below:

1) I need the snippet to use rich text so I can format things in bold as with the gutenberg editor.

2) the post previews (before clicking on the post) show the short code instead of the snippet content

If anyone knows what I could use for this that would be appreciated.