Idea for how to increase mountain height without lag.

If you make massive towering mountains a structure; not like a desert temple were every temple is the same but more of a woodland mansion were there are like a few different types and in those types there are more types. These mountains should be very rare just so it doesn’t get repetitive. But it should be like really high, 500 blocks or more. The build limit were the mountains generates would be higher but you would not have the lag of creating a massive mountain, its just copying a massive mountain.