Currently there is no documentation for the editableMeshOptions parameter of AssetService:CreateEditableMesh(), only listing it being of type Dictionary. This is in contrast to CreateEditableImage where it lists a size option there, however for CreateEditableMesh no options are listed and there’s no mention of it being unused.
Page URL: https://create.roblox.com/docs/reference/engine/classes/AssetService#CreateEditableMesh