For What It Is Worth
I flew 3 of these sorties - one 30 May 82, and 2 on 31 May 82.
Once the LGB kits had been delivered to us, we were keen to try them as we had not had any practice with them, but there were no ground-based folk in the right place to designate for us. So it was decided to try using the GR3 LRMTS to designate. Note, in the alphabet soup of LRMTS, there is no D - so it was not designed as a designator. Our info at the time said that it might work - we found out that it didn't.
The cunning plan was for two GR3's to fly the mission. The target area for the trial was the airfield at Stanley - so no chance of collateral damage. Stanley airfield was very well defended, but there was nothing on the ground there that could reach up to touch you if you were above 20,000 ft. Apart from Day 1 and, perhaps one other occasion, to the best of my recollection there had been no missile-armed Arg aircraft over the island, so we considered the air above 20,000' - certainly above 25,000' - to be "safe".
So we flew towards the airfield in trail, at about 35,000'. The front aircraft dropped the bombs at was considered to be a reasonable spot for a ballistic trajectory to get the bombs near to the centre of the runway. I was in trail, and once the bombs had been dropped, I entered a 30 deg dive, with the nozzles in the Braking Stop to minimise acceleration, and increase time in the dive, because I needed to recover above 20,000' as I did not want to put my nose into the shark infested custard below where they could have sent something up which would have spoiled my day. I put the target symbol on the mid-point of the runway, fired the Laser Ranger, and waited for the bombs to go bang where I was aiming. They didn't. At 22,000' I had to stop and initiate recovery to stay above 20,000'.
We tried again the next day - that didn't work either. The third sortie was with a SHAR dropping the LGBs, hoping that their radar aided weapon aiming solution might be better than our wet finger in the wind and that it would work. It didn't - so we gave up and waited until we could get ground designation onto targets before using up any more of these V&A items.
We found out later that the frequency of our ranger was not sufficiently discrete to attract the seeker on the LGB.
Hope that helps.