As a point of reference, there’s a newer ZFS feature that will allow you to expand RAIDZ pools without creating new vdevs. Note, however, it doesn’t let you add or remove parity to change the RAIDZ level.

It’s rather new and will take some time for implementation into NAS platforms like TrueNAS.

https://github.com/openzfs/zfs/pull/15022

As the old adage goes… “You get what you pay for.” I’m leaning on those being unauthentic. The price is too low and I’ve not seen the “Hua Lai Jie” version of the LSI card.