Yes it will. The terms 'HDR Fox T2' and the abbreviation 'HDR' are used interchangeably in the HD/HDR Fox T2 thread. The 'R' indicated that the box is a recorder. The HD Fox T2 is not a recorder(out of the box).
The Fan package does work on the HDR, so go ahead, install it and set the minspeed to about 40% and keep an eye on the tempmon. If the box gets too hot, the Humax default control takes over and cranks the fan up to 100%(ish)
Thanks for the rapid and helpful reply Trev.