I really like the idea of this mod, but it seems based on the discussions that it is still a WIP with numerous issues. No update in 9 months; are you still working on it? If not, I might be willing to try my hand at finishing it, but I'm no expert.

I'm still interested in the mod, it's just a difficult one to develop because there's a lot of design decisions to tackle. Contrast this with the mod it's designed after, the map is unlimited it size. It did not seem like there was a whole lot of interest because I don't really see people talk about it that much. 0.17 is also going to change quite a few things, particularly with GUIs and developing that part now could cause headache.

Some features I want to add:
A GUI for placing equipment (incoming chests, incoming fluid tanks, this would allow support for mods like Bobs/Angels)
Multiplayer support (think Oarcine's separate spawns, where players have the option of joining another tank or starting their own)
Better late game support (like how to keep the map size down)
External weapons (Add a turret compartment. Defense turrets there can shoot at targets nearby)

I can understand that. The only feature I can speak for is External Weapons: Look at Schall Vehicle Turrets or Heavy Tank 2°Gen. The former is better since it allows for loading and unloading without losing ammo in the process. Both utilize a vehicle grid, similar to a modular / power armor grid.

There is one design choice I didn't agree with when I tried the senario... the tank not stopping even when working inside of it. Made me paranoid to even work on the tank since I figured I'd just end up running into the middle of a massive bitter cluster. It would be nice to just have it as a true mobile base, moving from location to location but of course, the longer you linger in a single cluster or region, the higher the chances of large swarms of biters homing in on you, forcing you to try to judge how long you can stay in a location before risking a massed attack.

Speaking of which; How did you set up the whole "tank is bigger on the inside" and stuff. I took a look at the code but I couldn't wrap my head around it (was a while ago and I've been playing with other mods since). I'd love to have that feature on a vehicle like the Heavy Tank from Heavy Tank 2°Gen.

The inside of the tank works using a separate surface. The GUI teleports the player between the default surface and the tank internal surface.

The current version of this can be hosted as a multiplayer server without requiring clients to download the mod. If I were to use vehicle grids for external weaponry I would lose that functionality. But of course I would also have to fix multiplayer.

maybe add a turret upgrade that can add a auto shooting 5 bullet per second to the tank that auto shoots but consumes ammo from the tanks inventory (trunk)

I played NESTT before. I'm not really good with cramped spaces but it was a really cool experience anyways. Please keep the legacy alive :3