Yes,
a very old and a bit unclear one here :
.
.
have a read there :
The 6 ways to build pmos for samsung-espresso10 and flash it to the device (tested by Piero-e)
and there :
How to “dualboot” androidOS / postmarketOS (Piero-e 's contribution)
build pmos for running system from the SDcard is my recommandation in this case.