I fear I did not understand well your concern. did you have STPMIC1 in your solution ?
Without STPMIC1, the power off should be managed by your HW, and maybe a GPIO output could be used as a power off request.
Otherwise, using IWDG (watchdog) might be enough to catch application issue (there is probably some option also to have health checking done by specific secure application, e.g. in op-TEE, protected by IWDG).
I have STPIMIC1 in my system and i made PONKEY as toothpick button. But now the costumer wants me to make the main power button as PONKEY so if there an issue with the OS he could power off the board. i will made some changes in HW in next revision but i wondering if there is a ay to logically connect gpio pin to PONKEY interrupt ?
There is no way to do that. As you mention, only HW change is possible.
STPMIC1 PONKEYn is handled inside the PMIC to power ON or OFF (e.g. long press) the platform, this cannot be done using a STM32MP15 GPIO input.