Hi, it seems that you have created one of the best mods for the new planet. I discovered that if I create a new game in the sandbox, immediately go to Carna, and use the console command to open 4000 map chunks (approximately how many can be opened in the late game), after the map opens, on my new computer with an Intel Core i5-13600 processor, the UPS drops to 28, which seems like it shouldn't be normal. Here is the command, just in case:

/c local radius=4000
game.player.force.chart(game.player.surface, {{game.player.position.x-radius, game.player.position.y-radius}, {game.player.position.x+radius, game.player.position.y+radius}})

Carna nor its design takes into any account on using player commands to do anything, it relies on natural game generation, otherwise it may result in objects not spawning and breaking mechanics or freezing and corrupting your world. You're best not using commands when playing the game is the best I can tell you, I have no way of fixing this.

UPS may take an impact when naturally generating chunks, but this is due to the number of objects spawning tiles, it goes away after generation is complete.

This command does not do anything special; it simply reveals the map, just as a player would. I like to play with reduced resources and use this command to check if there are any problems with their generation. On other planets with enemies, UPS does not decrease from this; it seems that something is wrong with some objects, possibly enemies, which for some reason consume a lot of UPS.
In this case, the only possible option for playing Carna is to increase the amount of resources when creating the world in order to minimize the need to explore the map, otherwise the UPS will gradually drop even on good computers.

It is not the enemies, it is likely the beacons that are generated from every chunk being spawned. I have no experience doing anything with playing with commands, so I can't really do anything about this, I only ever play the game normally without the usage of commands, but I can ascertain that there is a significant difference in result when spawning the chunks on Carna normally vs using the command and the command results in various things not generating on Carna normally.

My small experience of Carna play say that amHunter is right. At first we slowly scouted map, later we used artillery to clean all enemies that were in range of manual fire. Explored radius was way bigger than any healthy base could require. We have sometimes ups drops, but we use giant mod pack, but still we are almost always at 60 UPS.
This is best looking planet ever. I even didn't want to deconstruct ruins, they are so cool.