How could I change visibility of multiple objects in the same position and bake lightmaps for each one correctly?

What do you mean by ‘change some objects with widgets’? That’s really vague when it comes to getting help in building a method for accomplishing something so different in functionality. Rewrite the post and re-post it. What’s written is way too difficult to comprehend for others in offering help. Perhaps sketch a diagram of the functionality, and/or include a few screenshots of the current workup.