LGBT is probably the least of problems for average Muslims in the UK, there are far greater issues that have become widespread and ingrained and it is only getting worse.
The reason I say this is that one can easily observe among young Muslims in the UK raised in traditional communities the word "gay" is considered an insult and is far from any kind of mass acceptance. Muslims in the UK have held onto the cultural stigma regarding this which the British formerly held, a simple look at the words they use with regard to someone they perceive to be "gay" is identical to what the average Briton would use in the 1980s/1990s.
In fact the current reaction to LGBT itself among Muslims seems to be a result of it being culturally unacceptable, whereas Muslim children brought up in the West have been exposed to a society with many evils, the worst of them being kufr of its many shades in the forms of atheism/agnosticism, secularism, liberalism, modernism, feminism etc which is prevalent everywhere, including in schools and colleges, yet there is little reaction or care for such exposure and indoctrination.
I feel it is sufficient to mention the Islamic prohibition relating to these matters and the how there is no room for difference of opinion as such things are qatyi, along with the fundamental aspect, which is often completely ignored and left out when dealing with modern issues, that the morality of the Muslim is based upon the Shari'ah, and that whatever the Shari'ah declared as evil is evil, and whatever the Shari'ah declared as good is good, that as Muslims we believe in all that RasulAllah ﷺ came with, that we make him ﷺ the ultimate created authority on any matter, and we submit to his verdict wholeheartedly, this is faith and this is Islam, and this is an important part of Islamic creed which I feel is not stressed enough in our times.
Yes, we can also mention wisdoms behind particular laws of the Shari'ah, however the fundamental principle of submission, acceptance, and deference should always be there, "we hear and we obey", it is this which must be inculcated in children from a young age, and it is the lack of this which leads people to reject parts of the Shari'ah or the totality of it.
In the course of apologetics and da'wah it seems many have forgotten what Islam actually is; submission unto Allah and His Rasul ﷺ in all matters, even if it contradicts modern norms, even if society today sees what they have declared evil as good or sees what they have declared good as evil.
If this is firmly rooted in the hearts of children from a young age, one could mention any hukm of Shari'ah to them and they would accept it without any hesitation or doubt, and it is this which is the ultimate goal and perfect state of belief.