Convert an external SSD HFS RAID 0 set to APFS?

I have a LaCie Little Big Disk 1 TB Thunderbolt 2 external SSD containing two 500 GB SAMSUNG MZHPV512HDGL-00000 drives in Raid 0 configuration and I'm wondering if and how I might convert it from journaled HFS+ format to APFS that is supposedly optimized for SSDs. The drive is used for for fast audio-video processing but not for booting or storage, and works well. LaCie designed it to be managed by Apple RAID software; it's not a hardware RAID. My system is a late-2014 iMac 27" retina with 4 GHz i7 processor and 32 GB RAM running High Sierra 10.13.2. Its single internal SSD was converted to APFS during the High Sierra upgrade.

Disk Utility does not show "Convert to APFS..." for the Lacie RAID volume, but does offer to "Erase" it with APFS included in the list of selectable formats. It also offers to "Delete RAID...", after which I suppose it should be possible to reformat the individual drives as APFS and then recombine them into an APFS RAID 0 set. I'm reluctant to try either without clear guidance.

Apple states that "Apple File System does not directly implement software RAID; however APFS-formatted volumes can be combined with an Apple RAID volume to support Striping (RAID 0), Mirroring (RAID 1), and Concatenation (JBOD)." There are some descriptions on the web of creating internal APFS RAID 0 SSD sets to transfer the High Sierra OS to, but that's not the purpose here.

Can I do the conversion, and if so, what would be the best way? I'm comfortable with the terminal if that's best.

Thanks