That's what SLOG is for if the writes are synchronous or if you have many small files/ want to optimize the metadata speed look at the metadata special device, which can also store small files of configurable size.

ZFS of course has its limits too. But in my experience I feel much more confident (re)configuring it. You can tune the real world performance well enough especially if you can utilize some of the advanced features of ZFS like snapshots/ bookmarks + zfs-send/recv for backups. Because with LVM/ XFS you can certainly hack something together which will work pretty reliably too but with ZFS it's all integrated and well tested (because it is a common use case).