Actually quite a few people have gotten to the far lands in Beta 1.7 on foot without save modification or mods and they didn't fall through the world. Also as a matter of fact, you can get over 8 Million blocks out using an elytra and the nether in under 12 hours so this needs to be fixed no matter if it gets marked as "won't fix", I will still try to vote on other issues that help get rid of these types of bugs caused by overflowing numbers.
You can actually reproduce this with the u00a7 mod by typing the § symbol into the chat and pressing enter which will kick you due to an illegal character in chat.
Major Optimization needs to be done with rendering text to fix it. I can also confirm it occurs on 1.19.0 and it's super annoying
Tried to create a datapack that allows caves to generate below y=-64 and encountered this... I think that the only way that this could be temporarily fixed is by completely removing lava aquifers