"Minecraft Comes Alive - Reborn" is a mod that overhauls the villagers with new entities.

I tested how well it works with VillagerQuests, using your example datapack, and the result is:

• MCA Villagers display the quests button when we trade with them, but it is always disabled
• When I summon a normal villager and he gets assigned to a profession, the quests button turns enabled for him - so it works as expected with the normal villager. The fun fact is that, after that, the custom villagers start giving the quests of the last normal villager I interacted with - every single custom villager, even those with different professions.

Evidences:

1. All custom villagers have the quests button disabled.
   

2. Custom villagers don't display the "?" symbol above their heads
   

3. Interacting with any custom villager after the interaction with a normal villager enables the quests button, but it displays the quests from the last normal villager.
   
   

4. After switching back from the quests to the trades menu, I start seeing the last normal villager trades, doesn't matter which profession the custom villager has. In the example, I interacted with a farmer normal villager and then tried with the toolsmith custom villager.