XCOM 2 "Frost Bomb" immunities / vulnerabilities

The Sectopod and Gatekeeper are both highly resistant to the Frost Bomb, but it's not entirely clear how it works.
Here's how I think it works:

• They still take the -10 defense penalty, for the duration of the turn you freeze them on.
• They lose all their moves on the following turn (they don't just lose "one action point"), although I've seen a Gatekeeper thawing and shooting a civilian on the same turn. This could possibly just be a developer oversight.
• Freezing a Gatekeeper will still kill all of its Psi Zombies.

I haven't seen anything especially vulnerable to it, though Chryssalids do tend to pile up once activated, making it easy to freeze an entire pod. The Alien Rulers are susceptible, but not any more susceptible to Freeze effects than they are to, say, being stunned.

I have no idea how well LW2 muton elites fare against it, but you could probably get answers under xcom-2-long-war-2.