Hello Konami,
the STM32L5 is not available yet for mass market so the support on this chip is should go through your FAE.
Such information will be available with documentation and training that will be provided at same time as mass market launch.
By the way, setting TZEN back to 0 requires making a regression from RDP1 to RDP0. This information is available in the RM
But be careful, when in RDP1 you can only attach to the target in non secure mode. So, you must have a SW running on the target that starts in secure and switches in non secure. Then you can attach in hotplug and do the regression; TZ=0 RDP=0xAA
Best regards
Jocelyn
