I have enjoyed using HAProxy for my own projects. Currently on 1.9.15. I tried moving to 2.x, but my ACL's broke when I changed to HTX. "%" started matching everything. Maybe I just need to escape it now. The silent-drop no longer closes the connection silently on my side in 2.x. (5.7.7 kernel may be part of this equation). I've not had time to debug it really. I would love to move to 2.x for the enhanced options around caching.
Interesting, that is the first I have heard of a "%" matching problem. You might want to join the community on IRC/Slack and share your config. I'd be more than happy to give you some pointers around upgrading to 2.x.
Thankyou, I will certainly look into joining the IRC channel.
Freenode #haproxy
Very exciting times! Author of blog post here I'd be more than happy to answer any questions about this release.