Version 1.4.0 introduced a hidden feature for gradient blending. If you use the XML editor to add the hidden setting
embroider_end_row_spacing_mm, you’ll get an effect like the one described in #78, Exponent Modifier for Fill and Satin (just the fill part).
It isn’t quite ready for prime-time, so it’s not added to the UI yet. Notably, certain shapes with complicated holes seem to cause the autofill algorithm to run forever and never finish, and you have to kill the process manually. But for most shapes, it seems to do the job. Combine two such fills going in opposing directions and you’d get a gradient fill.
Here’s a Tutorial file