jq is mot custom syntax though, it is just JSONPath standarsld. Which is also used to query JSON in JSON fields in MySQL for instance.

I wasn’t completely clear I think. I currently have 1*mirror vdev of 8TB each disk. I’m thinking of adding another mirror vdev of the same capacity. That would stripe the data between both. Meaning that per vdev there would be less data. That would lead to quicker (thus safer?) resilversing in the case of a singular disk failure per vdev, correct?

I’m not sure exactly what your setup is, if you have data in the OS pool that might be gone, unless you can boot the system from a stick and mount that disk to copy data over. Zpool export isn’t strictly necessary.

If your data is in a different pool then it should be theoretically easy to just import that pool in a new install.