Oh, that's a relief! haha
At first, the repair machine could be used in any order, but then there was a rare chance of hard locking the game this way, so i decided to make sure the player used the repair machine to get the mandatory item first.
To be honest, the only hint that the materials could be used to make the module in the repair machine would only appear if you checked it after defeating the boss, but you figured it out without the hint haha
Thanks for the info. Feel free to reply in the comments about anything in the game, bug or not.