Would love to see the setup and take a look at it. There has to be something else slowing it down that isnt being used in the editor. I assume when your getting 120 you are playing it via “play”, and, i assume you are getting 10-15FPS from playing in the actual game. This correct?
Are you running any other BPs?
Did you just drop your map in place of landscape in the island map?
did you add anything else to it?
whats the BP setup look like? did you use the day night cycle set?
is this literally a flat block with a player start and your having trouble loading it in ARK (outside the dev kit) ?
Sadly, from my experience, dev kit play /= what happens after you cook. I am not sure what the issue is between the dev and the cook.
I have no issues taking a look at what you are using right now. If you want to compress and send the mod over, i dont care either way.