According to
Discogs he's been active, but he quit trance early on. He shifted to the "Border Community techno" in the early 2000s and then produced really weird stuff for his 2006 album The Idiots Are Winning. Then, I think he had a hiatus until he came back with Triangle Folds in 2010 and several single releases in 2013 plus his album The Inheritors, which is more like IDM/experimental. Since then he's been doing other experimental stuff, like his 2017 album
The Animal Spirits. Finally, he wrote the OST for a British documentary.
I would say that Holden, much like Andy Blueman, is taking his talents to movie OSTs. That's probably the best outcome for someone with his ambitions.