I'll get that checked out. I haven't really ever bothered to read the Unchained Action Economy rules before, but from a quick glance over them, it doesn't look like it would be too much trouble to implement.
I've implemented support for this in v0.9.3 now. As stated before I've never actually used the Unchained Action Economy, so if you spot any wrongdoings, feel free to open another issue and I'll get them addressed.
Title says it all. Would be awesome!