Compression on the backing device?

I was thinking more towards mTHP which have a higher potential compression ratio. On x86_64 anonymous mTHP start at 16K (for completeness: shared memory mTHP start at 8K for some reason). Given that I see compression ratios >3 with plain 4K pages when using zstd, one compressed 16K mTHP might just fit inside a single 4K block, for example, but not more that two 4K blocks. That'd be a >100% increase in I/O throughput, on average.