I very much like the idea of where this is going, the tech bonuses are interesting and the challenge is beginner right now.
Some ideas of where to go would be new turrets, those are popular
mortars that are slower firing than rockets and aimed more at softening would be interesting
playing around with long ranged "tactical cruise missiles" something aimed more at plonking large groups but doesnt matter as much to invalidate hordes like krastorio 2 laser artillery did
Other assorted turrets to play with like a red alert style flame tower
In terms of enemies, this thing is ripe to play with the enemy race manager mod as either red army or terrans
Id also suggest looking at factorio+ for how they made their ruins bases, or even use the ruins mod and stamp out some proper hostile bases
Style wise, the command and factorio mod could be a very interesting nondependency
Along with some of the other tank mods like https://mods.factorio.com/mod/tanks_for_bob_fork
Adding in something like the space exploration meteors or some actually damaging lightning storms without lightning rods would be interesting
Reinforce this planet died for a reason
Altogether I think this is an excellent start and does very well at giving without being one of those ugh 100 playthroughs and its this part again feeling
