Is "snorkel in" back in fashion?

. Yes there some Italian research/ paper to support it, in the context of spearfishing.
When I started snorkeling as a child it took me a while to get used to diving snorkel in and blowing the snorkel clear on surfacing but once learnt it becomes second nature and I have stuck with it for decades now. There is no special trick. I did try snorkel-out briefly but it seemed very inconvenient to me.
That said, I had some problems with my usually good Omer Zoom snorkel yesterday. Like most modern snorkels it is about an inch too short IMHO. The sea had a low level, high frequency, chop - and every now and then it would fill my snorkel after I'd cleared it or interfere with the clearing.
It is also possible that I am a bit rusty, as it was my first dive for sometime and I was mainly getting re- acquainted with my gear as Viz was poor (did manage to briefly glimpse 2 mullet and a small Pollock though, through the haze). I had to switch from my usual 90cm speargun, mid-dive - as I couldn't see the end of the spear - to my 60cm "last resort" speargun.