There's quite a lot published on the XP55 that I've found quite recently, although as it happens I've found myself much more interested in the (not very well documented) XP-79B nasty, which occurred on it's first (and only) flight.
I'm not convinced that very much is published about the actual technical detail of the dH108 accidents - I've come across a lot about the events around it but suspect that at the end of the day not much was really known about how and why the aircraft lost control. If, however, somebody can prove me wrong then I shall be in their debt.
G