I am thinking of changing the map on my server to the Fjordur map when it releases, but I don't want to lose all the server settings. Can I change maps without losing the server settings?

Would like to know the same

So, you can change maps and not lose your settings, but your current save game is a bit different due to how ARK's file cleanup works on servers. If you want to retain your save game, it's recommended you make a backup of the current server before changing the map.

Also, to note, some maps (like Rag, Genesis, Ab) have map specific settings that may conflict or cause unusual behavior on other maps. It's heavily recommended you check if you have any such advanced or expert settings input before just carbon copying from one map to the other.

I'm more concerned with things under the advanced settings (harvest rates, xp gain, egg rates, maturation, etc.) I absolutely hate having to go through them every time I create a server. So, if I can avoid it, I'd like to. LoL

Oh, that stays when you toggle the map on basic or mod tab.