Ah, yes, the workaround. Yes, you are right, I made that discovery a few days ago.
Indeed, when I browse Mastodon through my own instance and happen to find your post, I can indeed reply.
However, the easiest method for me is to just go to the explore/local/federated pages of other instances directly. I can find much more doing it that way, and that's also how I found your original post.
I just opened the explore page of a large instance, and just randomly saw your post.