Hi, glad to hear you enjoyed the game! :D
There are several miscellaneous endings you can get thorough the game, but the last one depends on which, let’s say ‘group’ you chose to work with, if that makes sense without the spoilers. It’s a minor, flavor change, seeing as the VN ends there, so I don’t think you need to replay because you’re not missing much.
As for Reed-specific endings, aside from the minor endings in his route, there aren’t any extras in the public version of the game. There will be more choices and outcomes added in the Interactive Fiction version of Perfumare - Avulsion, though, and you can find the game on my profile.
The pre-ending scenes are different for each character, but the very last scene ending is the same for all routes, with a flavor variation as to what I mentioned earlier. I do have a guide for chapter V, since it contains the most miscellaneous endings, and you can find it along some snippets on my ko-fi, all free to read.