I’m pretty sure you can already do this (scale the HUD) for profiles that have UI layers assigned – even in Z3D or 2D mode. If the HUD sliders are visible on the vorpX menu Image Settings page, then something has been assigned. If there are no HUD sliders visible, that means nothing has been assigned yet.
You can use the G3D shader authoring tool (Ctrl+End) to seek the UI shaders and assign them to HUD treatment. You might have to temporarily enable G3D rendering to do this, but once you have assigned the right layers to be treated as HUD, you can then disable G3D and now be able to scale the HUD from vorpX menu in any 3D mode. Or at least you can do this with dx11 games, but maybe not dx12.
Edit: oh great Ralf. Thanks.
Any way we can add “do not render” assignments that apply to Z3D as well? I’ve been using the “hide shader” scan tool to temporarily hide depth breaking transparent window glass shaders in Mafia Definitive and RDR2, but having a proper toggle for things like that and unwanted crosshair/hud elements might be better.