I'm trying to use carpet and carpet-shadow together to spawn a fake player and use an XP farm to continually mend a pickaxe; however, I'm having difficulty transferring the (otherwise stable) shadow pick to the fake player; it always ends up duplicating instead of dropping the shadow item.

Is there a setting I'm missing, or is it basically impossible to do this?

These are the settings I've got enabled in carpet and carpet-shadow.

i'm sorry for the delayed response
this is definitely a bug with the mod as the inventoryFragilityFixes is supposed to fix it for unstackables too

i'll try and analyze it during this week

No problem! Thanks for looking into it!

Also, I don't know if this matters or not, but I'm running 1.17.1, not 1.18.*.

i'm sorry that this is still open IRL stuff is taking priority so i did not have the time to check it yet