Incus 0.x releases are as stable and on a similar schedule to LXD 5.x releases.
The reason to stick to 0.x until the first LTS isn’t too denote a lack of stability or support but simply to avoid misaligned versions with other Linux Containers projects.
Incus will jump straight to 6.0 at the same time we release LXC and LXCFS 6.0.