Did you read the link? Additional disk swap is optional, and if for some reason you would still like to have one, it's easy to disable writeback, using just the RAM.
And even if one enables zswap and configures nothing else, compressing RAM and only swapping out to disk under extreme pressure is still the default behavior.
My experience has been that not only in reality the pool size is limited by the amount of swap space you've allocated, it's also uncompressed again when offloaded there which is ridiculous when you think about it.
And even if one enables zswap and configures nothing else, compressing RAM and only swapping out to disk under extreme pressure is still the default behavior.