Index of specific # as pinned post?

How could one have a pinned post holding an index of all posts of a specific # ?
“#” = grouping posts as in

Thanks for any insights on how to do this!

I think I may have found a way thanks to:

As indicated, it only works on my own domain:

I then change the link to myblogdomain.tld/tag:tagword
Maybe a future version of may have an easier incarnation to achieve this?

You may post a feature request so that interested users can vote it.