Sadly all that effort in 2016 to survey Cnoc Coinnich hasn’t changed much. The online OS mapping app I have is still showing the old height of 761m. 
Edit: Just noticed the 764m height is shown correctly on the 1:25K map but 761m is still shown on the 1:50K map.
Thanks for the update. I did expect the above one. That’ll add another 2km onto what is already a long hike for someone doing it along with Culardoch GM/ES-015
Do them separately then. Just because there are 2 summits reasonably close doesn’t mean they have to be done in the same session. That pair are an obvious candidate for bike access especially as I have done the walk in 2 and half times.
It has just been announced that Giur-bheinn GM/SI-142 is not longer Marilyn so therefore will be another GM SOTA summit that will need to be deleted.
"Alan Dawson ad.staclee@gmail.com
Tue 25/05/2021 21:06
To:
News from Islay:
Giur-bheinn is no longer a Marilyn. It is not in the RHB book but was added to the list in 1995 after an OS map increased its height from 316m to 318m, tilting the probability in its favour. I was finally able to survey it recently.
Summit 317.4m at NR 3798 7286
Col 168.5m at NR 4008 7581
Drop 148.9m
The result is no surprise as its status was always marginal. This may or may not be the last Marilyn demotion. Cliffe Hill in Sussex is highly marginal but retains its status at present.
Alan"
You will see that it mentioned that Cliffe Hill G/SE-014 is highly marginal but remains a Marilyn for the time being, if this hill looses its Marilyn status, this will also need to be deleted from the SOTA programme. Cheriton Hill G/SE-015 is confirmed to be no longer a Marilyn and will be removed from the SOTA programme after the 31st August.
Jimmy M0HGY