Warlock's and Gaseous Form

I feel like I have slept on the spell Gaseous Form. This one spell option provides...

  1. Flight

  2. Free movement through any opening

  3. Resistance to B/P/S

  4. Advantage on Str, Dex, and Con saves

  5. Range of Touch, so a familiar can deliver it to a remote target (party member locked in a cell for example)

  6. Effectively able to cloak your identity, and allows the ability to hide in unconventional locations.

The downsides are the not being able to attack or take actions, but a warlock could cast Armor of Agathys and even take the Cloak of Flies invocation to set up damage sources for enemies that get close or melee attack.

What are some other ways that this spell can be used that might not be conventionally thought of?