[edited: early-drones setting]
The nullius devs will directly support transport drones in the not too distant future. This is just compatibility mod for now so that drones can be used until they have time to test and merge. Which means I am reluctant to make balance changes because those were originally decided by the nullius team and they would have had good reason. Functionality changes really belong in the Transport Drones Continued mod itself or perhaps a mod on top of that offering more options. That being said there is definitely some weirdness with the tech progress that could use a fix.
Also somehow the config option for fuel type disappeares and defaults to steam
That was definitely a nullius decision. I can see the argument for a config option but I'm not sure if they would want that in core nullius. I'd imagine the best option here is once nullius supports this natively the Transport Drones Continued mod would make that option available.
In it's current state, the whole system is unusable until the 3rd tech.
I've added a startup setting "early drones":
Startup settings => Nullius Transport Drones Continued Compatibility => Early drones on
I think that should greatly improve the requirements and move drones to immediately after trains. Which I think is a very defensible place for it to be. The setting change should work for an existing save too. I'll consider making this the default actually since it seems much more logical to me
Thanks for the feedback