Using Mirage's Hall of Mirrors in railjack causes extreme lag for the user.

[DarkMarkX]

The moment you use Hall of Mirrors in a railjack as a client, you'll be unable to use any abilities, change to operator, or melee at all until the clones wear off. There's also a general lag issue that persists for the rest of the mission, even after the clones are gone. The lag causes enemy ships and the railjack to constantly skip around, even when you would normally have low latency to the host. These problems don't occur until you use hall of mirrors at least once.

I'm not sure if the problem occurs when hosting the mission, but it definitely does when joining someone as a client.