BerryBoot custom OS w multiple partitions?

[toconquer]

This is the kpartx scheme for FydeOS for Raspberry Pi which I'd like to add as a custom image. Any idea how to handle this many partitions? The documentation only mentions finding the ext4 partition with everything that's not boot or kernel.

root@server:/home/user# kpartx -av FydeOS_for_You_Pi400_v13.1.img

add map loop7p1 (253:1): 0 8388717 linear 7:7 5996544

add map loop7p2 (253:2): 0 49152 linear 7:7 20480

add map loop7p3 (253:3): 0 5578752 linear 7:7 417792

add map loop7p4 (253:4): 0 49152 linear 7:7 69632

add map loop7p5 (253:5): 0 4096 linear 7:7 413696

add map loop7p6 (253:6): 0 1 linear 7:7 16448

add map loop7p7 (253:7): 0 1 linear 7:7 16449

add map loop7p8 (253:8): 0 32768 linear 7:7 118784

add map loop7p9 (253:9): 0 1 linear 7:7 16450

add map loop7p10 (253:10): 0 1 linear 7:7 16451

add map loop7p11 (253:11): 0 16384 linear 7:7 64

add map loop7p12 (253:12): 0 131072 linear 7:7 282624