I use ItemInHandRenderer to render first person weapons. It works on fabric 1.21.11 but we need to figure out some compatibility issues with Iris, please and thanks.
I capture the scope image here and by this time the framebuffer is empty. I need Iris to expose a final image or not delete the original one. I render all my models using WorldRenderEvents.AFTER_ENTITIES. If I read at any other moment it will not work on vanilla so I cannot budge on this: