TBH, I really never saw the purpose of swap-caches.
Before you start a rant, I want to clear up that, when you have enough RAM, you don't really need a Swap-Partition.
Moreover, it wears out SSD-drives which should be avoided. Considering memory has turned very cheap in the last few years, I myself really recommend you to just buy your 16Gb-sticks and are good to go without putting to much IO-load on your hard-drive.
Even when you use a distribution like Gentoo, you can easily turn the Makeopts to 8 simultaneous tasks (on i7) without reaching the memory limit (only 8 Gb Max.).
Nevertheless, compressing the swap-file is a great concept and I am looking forward to what it will bring.
If you have a completely different opinion on this topic, please let me know!