RAID 1 mirroring the SSD is NOT supported
Now you could keep a spare SSD in the host and flag it as usable after the failure (I'd have to lab/test this), but I'm still not certain this would trigger a re-sync instead of a rebuild.
Lets talk about the real concern here. Rebuild overhead, and rebuild times. There are a few ways to mitigate it.
1. Deploy more SSD's and break up your disk groups into smaller failure domains (Possibly even dedicating SAS HBA's to each group).
2. configure FTT=2 for more important workloads that your are concerned about (not ideal).
3. Make sure you have deployed either 10Gbps or 40Gbps and set NIOC properly.
4. Make sure your using reliable SSD's that are on the HCL and flashed to the recommended firmware version.