I don't know anything about singing, but am I correct in saying that Jon's technique these days is very different to the old days. Hitting the high notes in always was effortless in the 90s. Today it's a strain and maybe the only reason he can do is because of a modified technique..

I agree with you I would love to know more about his voice / singing.
I've said this before I don't understand why it's such a taboo subject in all interviews, the blame for this has to go to the media not Jon, but nobody ever wants to talk to him about singing technique in detail or how is voice has progressed over the years, where he is trying to improve etc... Same goes for the other band members- nobody seems to ask Richie many interesting questions about guitar playing. It would be infinitely more interesting than the usual 'how do you stay together for 25 years'.