Since I had some free time finally, I updated my Kitchen to make it work with boot and recovery images from newer versions of android up to 11. Apart from that it will work like before, with qualcom and mtk images (tested by me). I don't know about other chips (rockchip, spreadtrum, kirin etc). I don't have any device to work on for testing other chipsets. For boot images with header version 3 and vendor boot images, the kitchen is still untested since I don't have such a device. Theoretically it unpacks and repacks those images but I don't know if they work in phones. Also, all images lose the AVB signature during unpack and repack, and you must use them with disabled vbmeta check, or you can sign them back with avbtool.py.
Bumped to version 2.6 after improved functionality and corrected small things in unpackbootimg.