why so complicated :-)
only 2 files are changed from V4.2 to V4.4.
so extract INITRD with cpio as describted above then
move or rename old 2 files e.g to hs_main.bak ….
and copy with cp -r -f only the new 2 files.
this works in vm AND on real hw (alix)
dont forget to upload project with V4.4