You can write a Copper list from scratch but it is hard.
Yes! The only problem is that I don't know how.
It could be easier if it was a way to inject the needed istructions in the allready existing copperlist of Amos Pro, or having a copy of that copperlist that one could just modify slightly and then just replace.
Could such a sprite trick be coded by some hardcore Assembler genius as an Amos Pro extension?
Sadly, I don't think it's really doable within AMOS, or AMOS Pro

The copperlist that it uses is dynamically changed on a regular basis (every VBL?) in order to do sprite tricks (e.g. more than 8 sprites, which is the normal hardware limit) and other AMOS related things.
Yes, you could probably copy AMOS's copperlist (though I don't recall finding how to get AMOS's own copperlist in the past) and create your own.
However, in doing so you disable all of AMOS's graphical functions!

Maybe if there is an internal pointer to the AMOS copperlist, you could copy it and create your own in an AMOS bank and then point to it??
But there is no guarantee that the AMOS graphical functions would continue to work.
Anyone have any other thoughts on this??