Hi Frank –
Thank you so much for the quick reply.
Yes that solved everything thank you.
I had already excluded from JS delay the main lyte-min.js (I had picked up on that) but I didn’t realise about the inline JS. As soon as I added that to the delay exclusions list, all the YT thumbnails loaded up with the page load, which was exactly what I wanted.
Thank you once again for your help, and I hope you have a wonderful Christmas and New Year!
Best regards,
pete