Deliberately causing unnecessary explosions on over-run damages the turbo, exhaust valves, the cats and also the silencers, if severe enough. I've seen resonators/silencers burst apart from pops and bangs maps. The pressure has to go somewhere.
Naturally, none of that happens immediately, but one or more of those things WILL happen eventually. The early signs of imminent ££s are disintigrated catalyst crumbs flying out of the tailpipe, and maybe a turbine wheel blade or two.
I think the fascination for bangs and flames stems from Rally cars, but those engines are built to handle it. Maram turbo shafts, inconel turbines, inconel exhaust valves, no cats, no silencers and they don't have to last many miles.
Of course people selling you the map are going to say "Yeah it's fine mate, don't worry about it". It's not their property to give a sh1t about.
It's your car, your money, but if you want the engine to last, I would leave the pops and bangs personally. Your local residents would probably appreciate it as well because frankly, it's obnoxious, annoying and about as cool as socks and sandals.
