I took a look at some of these. You have to be careful because some of the modes make the more brilliant colors look better (like “hue” blend mode) but they essentially defeat most of what filmic is doing (like basic tone mapping!). “lightness” didn’t seem to do much. “HSV value” had more effect overall, but made it look just like what maxRGB would do to the textures and color contrasts.
“darken” mode yields results that look surprisingly similar to bypassing gamut_check_RGB in the sunflower image, because it masks out the gamut mapping desat method from functioning at all in the upper end of the curve (adding white would lighten, so it is prevented) however a sneaky side effect of this is that it will also defeat any contrast adjustment that would have normally been accomplished by brightening. So imagine the upper half of the filmic s-curve (or even a traditional s-curve) becoming flattened back to “nominal”, while the lower half of the s-cure was allowed to remain “s-looking”. It may be that this doesn’t really visually matter on a particular image, so it could be useful.
But these blend modes are interesting and also present different ways to incrementally work around the core issue, so thanks for reminding me of those. Even though I use a few of the blend modes a lot in my own editing, I always like when I stumble onto what various blend modes can add to the toolset.