First of all, love the mod. Ever since slapmap was abandoned as of 1.17, I've been looking for something comparable to place images into the world.

That said, there's something very frustrating about placing images using this since they by default don't scale correctly and are placed a block away from the sign, meaning that if you want the image on your wall, you have to make a hole in the wall and place the sign in the hole.

Wouldn't it make more sense to be able to somehow manipulate paintings or maps (placed in Item Frames) using their NBT data instead? That way, you wouldn't have to rely on the !PS: data on the sign and wouldn't be limied to the character width limitation of signs. Say you have a minecraft:painting that contains the URL inside an NBT tag called PPurl (PicturePainting URL), it could fetch the image and automatically figure out the scale, formatting it to a 1x1, 1x2, 2x1 or 2x2 image, depending on what fits best.

Just a thought; I understand that it would require a rewrite of basically everything. ;)

You have some good ideas, however the mod is supposed to be survival-friendly and manipulating the NBT data requires OP privileges. I want users to have control about how it's scaled and where it's displayed, and at least in my builds using the mod, the current system with the scale and position in the last line works pretty well.

Last I checked, manipulating NBT data doesn't require OP privileges if it's the mod that's doing it and not the player. For example, in one of my mods I have a hook that sets an NBT boolean tag isPlayerPlaced to true if a player places a Spawner on the ground, so that a mixin at a later point can check if that NBT tag is set to determine if breaking the spawner should drop it or not.

Non-OPs placing and picking spawners behaves correctly, as the mod is doing the NBT tagging, not the player.