This update introduces a new modding tool for creating sets of ships and buildings for the AI to use in conquest. You can unlock it by going into the Settings and enabling "Modding Tools" there. You specify tiers of ships/buildings/landships for the AI to build. You can also tell it what ships should upgrade into other ships, or let it determine this automatically.
The technologies to research are automatically generated from the tiers you specify, but you can add additional techs to research, eg flamethrower or steel armour improvement techs.
The resulting fleets can be exported as mods and published to Steam. You can also open pre-existing built-in fleets to modify and improve them. There is also an informational panel on the side that gives rather opinionated guidance on how to make a fleet that the AI can use properly, with enough variety of designs and so on. Part of the reason for this new feature is that I want to overhaul the existing fleets in the game, so if you previously contributed a fleet, do have a look and get in touch.