Help needed in order to shrink boot.img for old device

Hello, first issue for me :)
I've been tinkering for a few years with Android Phones, mainly older Samsung flagships (Galaxy S1-S5). I've encountered an issue on the Galaxy Note II. I had it running as an embedded (web) server (like a raspberry pi). As some updates failed (edge I guess) I figured it would be quicker to just reflash from current edge.

That's when the trouble started. Long story short, it's become clear that the boot.img has increased a tad to much in size since the first installation of pmos.

• Note II BOOT partition has a fixed size of 8192K set in PIT (resizing is not possible - if you try to and boot you get strange cutoffs from the bootlogo).
• pmbootstrap generated a boot.img with a size of 8274K - not even 100K too big.

So I would need to shrink boot.img a little bit. No idea how to proceed. I have not found much info on the wiki and the internet - best I found is Boot process in the wiki and another (unresolved) #2011 (closed) issue with the exact same problem - boot.img too big, need to shrink it.

Any guidance on how to shrink boot.img is appreciated.

Maybe it would be useful to add some kind of check in the device-specific config files of older devices to ensure that boot.img fits into the devices boot partition while generating it.