PowerPath: How to configure an AIX host booting from SRDF devices?

Environment :
OS : AIX (any release) with boot from SAN configured.
DELL EMC SW : PowerPath 6.1 and above
DELL EMC SW : classical R1-R2 SRDF
DELL EMC SW : SRDF Metro
DELL EMC HW : VMAX family

DELL EMC doesn't officially support boot from SAN with PowerPath on SRDF R1/R2 devices on AIX, as opposed to Solaris or Linux where a "powercf -Z" can do the trick. Without precautions, the following symptom will be observed :

Initially, the host boots from a R1 device. lspv is then showing the following :

# lspv | grep rootvg
hdiskpower0     000b8d313342518d                    rootvg          active

Upon a reboot on the R2 device, lspv |grep rootvg now returns : 

# lspv | grep rootvg
hdiskpower0     000b8d313342518d                    rootvg          active      
hdiskpower41    000b8d313342518d                    rootvg          active

the duplicate PVID will not be an issue to boot, but will be an issue to varyon other VG. To avoid this kind of issue, PowerPath needs to be completely uninstalled and re-installed. "PowerPath updates" instead of "PowerPath uninstall / PowerPath install" sequence will cause the above issue.

If PowerPath is completely uninstalled and reinstalled, an "lspv | grep rootvg" will result in the following sequence :

boot from R1 device :
# lspv | grep rootvg
hdiskpower0     000b8d313342518d                    rootvg          active

Boot from R2 device :
# lspv | grep rootvg
hdiskpower41    000b8d313342518d                    rootvg          active

In an SRDF metro configuration, the above issue doesn't exist since, thanks to the identity spoofing mechanism. the host (and PowerPath) is not aware of the difference between the R1 and the R2 devices ... and everything works as it was a classical and regular boot from SAN.