The sure talk about having regen a lot. Seems interesting given the RPITA that it is to pull off with a DC setup. I know that EVNetics Soliton Jr is capable (at least according to one of the posts on the EVNetics website) of doing regen but they said that it wasnt the ideal setup.
When I worked with Zilla controllers we talked about bringing that same option and decided that it simply wasn't worth the extra hoops for marginal returns at least for now.
Best of luck to them.