Different event, similar issue on live: During the Heroes are Forged group mission, when the spider queen does her first port behind the webs, the instance always hitches. So although hitching has been largely improved/fixed for many scenarios, this is one reproducible scenario in which lag/delay/hitching always occurs for about 200-500 milliseconds.
I'm most interested in ensuring the dev actually sees the message due to it being a reply to. The cause is likely related, which Cairbrae has also been working on.
Or, you could actually follow their guidelines for reporting bugs. Its only stickied as the top post: - Discuss only one bug per thread. Please open additional threads as needed for multiple bugs.