Does this have any performance impact with regards to throughput or latency?
(Disclosure: I work with Mullvad on DAITA.)
This is tricky. We have hardly started dealing with traffic analysis issues in protocols. In general, we have spent the last decade+ getting encryption sort of right with amazing efforts like TLS 1.3 and WireGuard, etc. Expect another decade for traffic analysis.
It's similar to how encryption was viewed as too expensive a decade or two ago. Today, it is a necessity. Seeing how available bandwidth keeps growing to accommodate things like video, I hope traffic analysis defenses won't be as detrimental in the long run for most internet use.