Iain a charaid, thanks for the response.
As someone who doesn’t speak Gaelic, I am surprised at your certainty.
“Comhchag” is perfectly usable for Snowy Owl. Look at Òran na Comhchaig to see the relevance and longevity of this. It is used in this form and perfectly accessible.
The “head wall” English text came from the staff at Cairn Gorm. Please contact them to correct the error.
As you say yourself, you are presuming certain things. I would advise not doing this as often it’s incorrect as you demonstrate. A tweet on Twitter does not mean something is a factual reality and the information regarding Gaelic language plans is widely available to anyone caring to look for it.
It is maybe this reliance on presumptions and poor sources that allows you to conclude that you are indeed correct despite not speaking the language and multiple other sources disagreeing with you.
As someone who works with lots of others in Gaelic development and has seen the changes brought about, in part, by bilingual signs, I can say that the current methods do not detract from other work. Indeed the methods are used in many other countries and proven. I would go further and say that the presentation of text on signs in Scotland is superior to that in Ireland and Wales where one is in italics and the other the same colour as the English form.
I have already pointed out your errors such as your view of Haymarket which doesn’t hold any water. Plenty of Gaelic speakers use it.
Regarding Scotrail, why not just leave your text and recognise your error with an additional piece that says so?