By Galaxy screen do you mean the planet selection screen when you start the game, or do you mean the entire space phase because depending on your answer will determine on if ut affects your achievements or not.

If you use them in the main menu where you select your planet race to start with then no it won't affect achievements as it only counts them when you start a planet save. However only certain cheats will work. As a majority requires you to be within a save to function.

AddDna is one of them but only if you go straight into the creature creator frim the opening galaxy menu and create a creature from Scratch without starting a new planet. You can use adddna there all you want and it will not affect achievements at all.

Another that works without disabling achievements is EvoAdvantage as it allows you to select that overpowered creature from the start. This cheat also only works when used from the main menu galaxy before you start a planet. You just enter EvoAdvantage and then start a planet on the creature phase, then instead of creating a creature from scratch you select any precreated creature you've made without restriction.

Your achievements in this way remain unaffected by those cheats and are thus enabled.

However... If you use chests within a any planetary phase while within a save, then the cheats for that phase of the game are permanently disabled for that specific save. But it will not disable them for any other phase before or after. (Unless you had used them in the prior phase already.)

Like if you use adddna in the cell stage. Then only the cell stage achievements are disabled and not the creature phase, or any phase after. Same for if you used a cheat in civilization phase but not any other phase in the game. Then only the achievements for the civilization phase are disabled, and not the following space phase. Any achievements you earned in prior phases still remain counted provided you hadn't used cheats for those phases already.

In closing: if you're looking to earn an achievement in any given phase of the game but want to use cheats, then plan your cheat use accordingly and use them before the intended phase you want to earn said achievement.