Tilemap optimal size

Godot Version

Godot 4.3

Question

I am making an rpg game with a quite large map but when I exceed about 250x250 tiles the editor starts to lag when I change scenes. I have considered chunking but I think it’s out of scope of my project because I would also have to load/unload mobs and chests. What is the max recommended tilemap size for a lagless game and is there any way to optimize the tilemap. (My tilemap has collision layers, occlusion layer, z-index and navigation layers)

From the research I did it seems Godot 4.3 worsened the tilemap performance and now it starts to lag on way less tiles. Is there any way to fix that?