How do I update to minecraft java 1.18 WITHOUT altering old terrain?

I want to update my 1.17.1 survival vanilla world to minecraft 1.19 when it comes out and I can't find anywhere a way to update so that worlds don't modify existing terrain, I only want to get the new stuff in new chunks. I don't care about ugly chunk borders or anything like that, I just need a way to keep my chunks as they are right now. the closest I've seen to what I'm looking for is a small remark in here where they say:

Players who have opened a world with the Caves & Cliffs Experimental Toggle enabled when bedrock was still generating at y=0 will not receive new world generation features

but they don't go any further in the topic and searching for it I only get results for bedrock edition.

I also don't mind hopping between snapshots as long as they don't cause any nasty permanent side effects to worldgen other than what I'm looking for.

minecraft-java-edition technical-issues

Pictures about "How do I update to minecraft java 1.18 WITHOUT altering old terrain?"

How do I update to minecraft java 1.18 WITHOUT altering old terrain? - Old wooden barns on green hill

How do I update to minecraft java 1.18 WITHOUT altering old terrain? - Exterior of old masonry buildings with square shaped windows near dry sandy terrain with growing palm trees and grass under blue sky

How do I update to minecraft java 1.18 WITHOUT altering old terrain? - Top view of rough natural rock surface with cracks and orange rust as abstract background

How will Minecraft 1.18 Affect old worlds?

The most noticeable change is that the world height has changed. The game world now goes far deeper, so where there was previously bedrock, there is instead deep slate and potentially caves.

How do I update my Minecraft world to 1.18 1?

Open up the Minecraft Launcher and launch 1.18 (or one of the Release Candidates). Select Singleplayer, and select your world (do not load the world!!). Click on Edit, then select Optimize World. You can choose to erase cached data, as far as I know it does not make a difference for method 1.

Do new Minecraft updates affect old worlds?

When the Minecraft 1.19 update gets installed, it will add new features to the old world without disrupting any part of it. For example, players will see their world generated as usual, but if they go underground to find some new chunks, they may come across the new Deep Dark biome.

Converting Old Worlds To Minecraft 1.18

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Images: Matheus Bertelli, eberhard grossgasteiger, Henrik Le-Botos, Frank Cone