Different scale for x and y in a QGIS map layout

I’m making some geological cross sections with the geoscience plugin. I have been able to do this and I can make a print layout where I have my cross section (which the plugin makes in x-y space where y is really z) and the plan view on top and it looks great. Now what I can’t figure out if there is anyway to make a vertical exaggeration on the cross section (I don’t generally like doing that because all the angles end up wrong, but still need to). I cannot find a reference to different scaling on the x and y for qgis for a layout, and the only thing I have come up with is to define a custom coordinate system where the y (which here is really z) is scaled by a certain amount relative to x.
So my question is, is there an easier way to do this or is there a simple way to scale a custom coordinate system (I’m trying to get the affine to work)
Thanks