My character has the Vestigialist archetype for Warlock. I selected the Mobility expanded spell list specifically for Freedom of Movement and Greater Invisibility at 4th spell level. The Bewilderment, Fire, and Stars expanded spells list also have good choices for spells. However in each case, I think there's only a couple of spells that are worth choosing instead of spells from the Warlock's main spell list.
The spells that I have selected are:
Cantrips: Friends, Mage Hand, Prestidigitation
Level 1: Armor of Agathys (my go to for defense and when low on HP), Find Familiar (from Pact of the Chain), Hex
Level 2: Misty Step, Shatter, Shattering Barrage
Level 3: Dispel Magic, Hunger of Hadar
Level 4: Freedom of Movement, Sickening Radiance
I have yet to have a combat encounter where Hunger of Hadar was useful to cast, while I've used Dispel Magic 3 or 4 times now. So I swapped out Hunger of Hadar. And I have the rare spell Chains of Perdition, but I have yet to use that either.
Shatter is my default spell for area of effect damage. Eldritch Squall will also now be used that the character has reach 7th level Warlock. Fireball, particularly the rare variant, would still be better in many circumstances. I use Eldritch Ray or Eldritch Scythe for lower single target damage, or Shattering Barrage with Vestigialist's Curse and possibly Hex for higher single target damage.