The USB-UIRT is supported in lirc 0.8.1 with the "usb_uirt_raw" driver. The attached patch allows "usb_uirt_raw" as a valid option for LIRC_DEVICES, and worked for me.
Created attachment 113141 [details, diff] Add usb_uirt_raw as a valid option for LIRC_DEVICES
Added usb_uirt_raw to profiles/desc/lirc_devices, and to lirc-0.8.1.ebuild.