This is a feature request from Captain Obvious, and admittedly premature.
But, with Apple having announced today that they are moving all their iOS devices to APFS with their next point update to iOS 10, rather than waiting for the next major version, it seems timely to bring it up.
Although they’re moving iOS to APFS fairly soon with a point update, for their computers it seems likely they’ll wait for the next major version of macOS. With the direct manipulation of the filesystem on Macs, there will be a wider variety of use-cases —like Drobo use-cases— to accommodate.
It would be really cool if Drobo could begin supporting APFS once it’s out of beta in macOS. Apple apparently intends to seamlessly convert HFS+ volumes to APFS. Hopefully it will be nearly equally seamless for Drobo to do the same.