It looks like we currently don't respect SVG's color-interpolation attribute, https://svgwg.org/svg2-draft/painting.html#ColorInterpolation, for SVG gradients. Now that we can easily support linearSRGB interpolation, this should be easy to add.
Created attachment 448178 [details] WIP
<rdar://problem/87294645>
Firefox shipped this in version 123 [1], and I'm looking at getting this out the door in Chromium/Blink, so consider this a nudge to get the above patch out the door ;-). [1] https://www.mozilla.org/en-US/firefox/123.0/releasenotes/