"I watch such cinematic film waste, so you are not alone."
Hah! Well, we make no apologies for that.
"Actors who collect stamps are not rare. He is an actor, not an MMA fighter, just plays one on film. He does have some martial arts type training and experience."You're absolutely right, Adkins is not an MMA fighter. He
does have a black belt in Karate, and training in several other forms. But it would be questionable how well he would do in an actual fight with a professional MMA fighter. As you say, he does films, and with some excellent choreography, most of which, I believe is done by himself. On the other hand, his skills are far from insignificant. I mean, he could annihilate most people easily in actual fighting, I'll wager.
As to the stamps, who knows if it's actually a Scott Adkins hobby? In this clip, he's in the character of Boyka, and it was odd to see that character pursuing stamp collecting (albeit he was in prison, and presumably the implication was that he was killing time. I think we all know stamp collecting is good for that!

)
"...for decades stamp collecting gave me something to do when healing from my injuries from training and competition in the gentle way."I hear you load and clear.

Obviously, I see someone curating their stamp collection, I see nothing odd about that. Something about seeing that in the movie was odd, and I wondered, "why'd they put that in there?"
Here's a topic: A compliation of examples of stamp collecting in various media, movies, shows, books, etc, wherein there is some mention or scene of stamp collecting and which is
not central to the story or plot.