Resolved! Example code for SFIx variant of external loader
The following repository contains examples for creating 'normal' type of external loaders, i.e., to be used with the "-el" argument of the STM32CubeProgrammer (e.g., with output "STM32CubeProgrammer/bin/ExternalLoader/MX66UW1G45G_STM32H7S78-DK.stldr"...