Only asking.
Its good that they are covering the replacement of your winch if it was to be stolen off the vehicle that it is on..
Top Tip if they do & i will be trying them for a quote when i next need cover.
I do not know what your policy has as 'standard terms' (& exclusions) are concerning 'additional equipment' or 'accessories'.
Possibly the 'standard terms' are like those for Audio/radio equipment and 'tools' etc and cover to £1000 or whatever.
I only have my own experience of having one winch & bumper stolen,
and one winch bumper and winch damaged in a collision.
The winch that was stolen off a vehicle was on the declaration sheet for the 4x4 off road modified vehicle & photographed and had the original purchase receipt,
but when the winch and winch bumper was stolen it turned out it was not covered against theft,
it had just been accepted by the insurance as a added 'risk' but could not be claimed against.
(the winch mounting bolts had welds to stop them from been taken off without being cut or a grinder used, but they took the bumper and winch)
I was not surprised when i had a vehicle hit by another driver while parked, there was quite extensive frontal damage and the winch was damaged.
(i had asked obviously after the first experience, if a winch was covered against loss and told they were accepted as a fitment and modifiction but not covered against loss or damage.)
The repair was done under the insurance & the bumper was replaced like for like, as again it was Declared & pictured with a winch fitted for the 'Agreed Value Policy',
I had to pay the Excess which i never got back, even though i was not at fault, and the Insurance Company would not agree the replacement of the winch with the vehicles repair under the terms of the policy..
I have 2 vehicles with winches on vehicles and both are covered with declared mods but no cover against the winches.
But they are only £350 & £400 winches and the excess is £350, so i just try to be very carefull that they are not going anyplace
other than staying safely on the bumper.
george