Compiling from master doesn't generate bootable Orange Pi PC images any more

I thought some stupidity on my side for a while: At some point the PROJECT=Allwinner ARCH=arm DEVICE=H3 UBOOT_SYSTEM="orangepi-pc" make image doesn't generate bootable sd card images any more. I was just using some previously written card with an older image and just exchanged the KERNEL and SYSTEM with the newly compiled one (on the first partition). Which works without any problems. Only problem: It is quite tedious (slow) to clone a card to get a fresh booting version that way. Diffing the scripts/(mk)image files there are some changes ... but they do not look very dramatic to me. Any ideas? Thank you!