A remaking of Tleth's final stage

[Malekron]

Is it possible to add a bunch of Tentaculats & Biodrones guarding the Great Dreamer to the map in the final stage of Terror from the Deep or create a new map for a fresh gameplay for both seasoned vets and new players to navigate instead of the rather weak vanilla last stage full of Deep Ones and Lobsterman.

[Hobbes]

Is it possible to add a bunch of Tentaculats & Biodrones guarding the Great Dreamer to the map in the final stage of Terror from the Deep or create a new map for a fresh gameplay for both seasoned vets and new players to navigate instead of the rather weak vanilla last stage full of Deep Ones and Lobsterman.

Yes for both. To add Tentaculats/Biodrones you'll simply need to change the alienDeployment settings on the ruleset for the final mission. And you can create a new map for it.

But in both cases you'll need to wait until TFTD is released.