The recipes seem very similar to each other, it would be cool if the recipes were unique for each level of thrusters

Hi!
Recipes were made as they made for several reasons:

1) Inheritance of generations. Recipe of each generation represent additions and modifications made to previous generation to make more efficient and powerful thruster. That is why recipes of next generations contain elements from previous (not replace them);

2) Logical consistency. Elements of recipes represent technologies used to make thrusters better: tungsten - temperature endurance, holmium - electronics enhancement, efficiency module - more efficient fuel burning, productivity module - more fuel can be burned at once and make more thrust;

3) Game balance. Thruster MK2 can be made when you visit at least 2 planets (Vulcanus and Gleba) - mid-game, Thruster MK3 can be made when you visit at least 3 planets (Vulcanus, Gleba and Fulgora) - late-game. Additional elements (modules, tungsten and holmium) were chosen considering technologies provided by planets, element uniqueness and assembling / production cost - also for maintaining game balance.

If you have ideas how to improve recipes without violation of these three concepts, I would be really glad to consider your suggestions.

Thanks for your interest to the mod!

To be honest, I'm planning to add a bit more content to the mod in the future. I consider to add another approach to get more thrust in the next update. Maybe it will solve the issue :)

I think it's better to use level 2 modules for the MK2 version. In the MK3 version, I think you could replace the "holmium plate" with a "supercapacitor," and you could also add a "quantum processor" to the recipe.

I also recommend replacing the icons on the Thruster mk2 and mk3 so they don't merge.

As I think:

1) Level 2 modules for MK2 look reasonable and worth considering;

2) Replacing holmium plates with supercapacitors also looks reasonable and worth considering;

3) Quantum processors are super-late game items that can be unlocked on Aquilo (adding them will break the initial idea of balance). They also already used in Fusion Thruster mod that provides player with super-late game solution after unlocking Aquilo - https://mods.factorio.com/mod/fusion-thruster;

4) Lack of custom graphics is a known issue and I would be glad to get some help with it or take some advice on how to make custom graphics simple way, because I am amateur in it.

Thanks for suggestions!

Added simple custom icons for Thruster MK2 and Thruster MK3.

Thank you, I'm very glad that you listened to me.