Achievements still are allowed despite the server granting you privileges

If I host the server, I can use "gamemode 1" on one of my devices and as long as cheats are technically disabled, it works. If I edit the files so I give 40 damage compared to 1, I am able to get the "Overkill" Achievement.

While on creative, I was able to enter the end, and got the "End" Achievement (something like that). When I killed the dragon, I got the achievement for that.

I enjoy playing around with the dedicated server, but if someone isn't interested in playing on that thing for achievements, and changes a file, they may inadvertently get an achievement for something that they didn't want.

I do not have video evidence. If you want some, feel free to ask and I can record something.
(Downside is I'd get an achievement I'd want for my survival world)