Took me a bit to find this June 2016 post from Coconut. It fixed my cold engine idle up issues a while back. Might be worth the try.

"You can reset the Engine Management Adaption without spending a Penny ( or a Cent ! ),
and without having to undo a single screw, or connect anything at all to the Trophy !
From the Service Manual :
Ensure the engine is COLD
WITHOUT TOUCHING THE THROTTLE,
Start the engine and allow it to warm up until the Cooling Fan comes on.
Leave the engine to idle for a further 12 minutes.
Note :
After the engine management adaptation has been reset on the Trophy,
the Cruise Control Switch Check Function Test must ( may have to ? ) be performed.
After the adaptions have been reset DTC1575 will be stored
(cruise control disabled until button press sequence completed),
and the cruise control disabled, until the function test is completed.
The windscreen motor will cycle from fully up to fully down
during engine management adaption reset.
I believe that the above Note only refers to Adaption carried out using Triumph Diagnostic tools,
and not the Manual procedure, however if the Cruise Control Switch Check Function Test is required,
( check to see if DTC 1575 has been stored ) and will also be indicated by the Green Cruise Control
Warnng Light iilluminating when the Igniton is switched on, but the Cruise control will not activate.
This Function Test is carried out when connected to the Triumph Diagnostic equipment,
or by using after market tools such as "DealerTool", which is referenced eslewhere in these Forums ,
and involves operating the following switches in sequence :
Front Brake Switch
Rear Brake Switch
Clutch Switch
Twist Grip cruise cancel switch ( roll twist grip forwards )
Cruise Control ON/OFF switch
Crusie Control accellerate switch
Cruise Control decellerate switch
Regards,"