Hi Giovanni,
Thanks for the example. The outline shader here differs from your previous MinimalShader as it would require a stored depth texture as it makes additional samples with offsets. Depth buffer fetching would only work for the current destination texel. The EarlyZ pass would indeed generate a stored texture prior to the color pass (iOS devices tile based GPUs and render targets cannot be sampled until the generating pass is complete and contents stored) making this approach functional, however the additional cost of EarlyZ may not be worth it. To avoid the need for EarlyZ, outlinetest would preferably setup a post process pass and render its screenspace effect there, which would be occur the base pass, ensuring that the depth texture is stored and current to the running frame rather than containing the stored results of the previous frame if sampled within the base pass. See https://dev.epicgames.com/community/learning/knowledge\-base/0ql6/unreal\-engine\-using\-sceneviewextension\-to\-extend\-the\-rendering\-system for an example of a post processing pass setup via sceneviewextension. If you need further assistance, don’t hesitate to reach out again.
Best regards.