Less and less sound is reflected as an echo and more of it gets absorbed by walls every time sound bounces off a surface. Not a good argument.
Mh yeah there is still echo, the miner literally noticed Viktor when he was some meters away, he still would have hear the sound before coming in the place, for sure the sound didn't disappear 10 meters away from Viktor, also looked for a video to have an idea about the sound and in a mine it goes very deep tho, the one I heard was from an little explosive so yeah I assume it was more powerful but you could hear it from meters and meters away without any problem and it was also strong, I believe a punch with that impact and DC spreads for not only some meters, even because the author clearly wanted to say the sound was very strong with the booms. So yeah definitely he would have hear it earlier while coming.
Viktor literally says "Iron Punch" on panel three times, which wouldn't make sense if he only threw one punch. If anything, three punches is a lowball as we don't know how long Viktor was in there.
In this case he said "iron punch" two times (and not three as you said) but there are three booms so at least we can say booms =/= number of punches, between the times he says it and the booms I would rater say that the number of punches = number of times he says it but it is also wrong, in the mountain we only see him throwing one punch but he says "mountain punch" two times, in the tornado scene probably he wasn't even punching and still said "tornado punch" two times, in the magma scene we see him only throwing his right punch and still he says "magma punch" two times, in the tsunami part we don't see him punching at all but just because he was small from the POV but we know that with his left arm he was holding the tip of the ship therefore he could have only throw one punch and still he said it two times, after there is the lighting part where he literally didn't move at all and said "lighting punch" only one time but still said it when he didn't even throw a single punch, for the ice one we see that he threw at least three punches and still said it only one time, after there is the iron part, after there is the gatling part when he threw 10 to 15 punches and he only said it one time and for last we have the holy punch where again he didn't move at all and still said "holy punch" therefore number of punches =/= number of times he says "X punch" is heavily inconsistent in each scenario. So booms and times he said "iron punch" have nothing to do with how many punches he threw and I want to say again the booms come after that punch so there is no way they derives from the punches and so the booms are the echo which comes from the sound of the destroyed rock. The scene is this: 1) the miners are coming in 2) a miner sees Viktor and says "huh" since he surprised and didn't expect someone in the mine 3) we see Viktor's punch is going to land 4) we see the punch with the hole and hear the booms, for the whole scene we don't see booms anywhere and the miner had to see Viktor and being some meters away from him (like 10 m) to know he was there, if he was punching from the start (when the miners were coming in) we probably would have had a scene like the miner saying "what are these sounds?" or at least we would have heard a boom when the miner said "huh" because he was already in front of Viktor so he would have heard something for sure.
It also doesn't make sense for only Viktor's last punch to be dramatically stronger than his other ones.
It still may happen, in fiction I've seen many situations like this, if I'm not wrong in re5 Chris is trying to push a rock by punching it and the first hits don't have effect and only the last one moves it (is just an example), I know it doesn't make much sense but it still may happen but I think saying only one single punch is more correct.
Additionally saying that 95% of it was pulverized because only a couple fragments were seen isn't a good argument, given how authors frequently won't bother with drawing rubble. Not to mention there's a giant minecart full of rubble that Andrei Vlascenko and Tommy Maguire (His trainer and the reporter) are sitting in in the scene.
Alright, so you are telling me he each time he punched he took the rocks an put them there but for some reasons with last punch we only see like 5 very little rocks which are clearly very very smaller than the one in the mine cart and we don't see him even picking them, also I want to add that the total volume of the rocks in the mine cart is clearly higher than the volume Viktor destroyed, I want to add that 2 CGMs already agreed with the calc and one specifically said that pulverization is better in this situation than vfrag.
And even if this calc and its assumptions were accurate, it'd still be an outlier given how Viktor can be seen continuously punching the top of Mount Everest in the previous chapter ("MOUNTAIN PUNCH!"), and ice in Antarctica in the same chapter as the Mineshaft punch feat ("ICE PUNCH!"), and he does nowhere near the same amount of damage, further supporting the idea that Viktor had been in the mine for some time.
For the mountain scene you don't see both if there is damage or if there is no damage also not doing something =/= not be able to do something, with this logic Naruto isn't planetary because he doesn't destroy the planet every time he attacks, for the "ice punch" he was in fact punching ice and snow but even if he was punching the land not doing something =/= not be able to do something, his punches are considered incredibly strong from the first time we see him they are even compared to Aaron's one (an Aaron who holds back of course).
Probably the author in that situation wanted to show how strong Viktor's punch is in a clear way since from the start the author is saying how strong he is, there is not even a big jump to call it outlier considering an holding back Aaron is already wall level (using the statement "Sorry I don't know how to hold back" is wrong because we literally see him holding back because he normally doesn't want to kill the people and we only see him going all out against Yu since it was the first time he needed to kill someone to don't die himself) and again his punches are compared to an extremely holding back Aaron's ones which are easily at least wall level.
Viktor never said things like "oh no I can't destroy a wall" which would contradict the feat so calling this feat an outlier is wrong and just doesn't make sense just because he didn't perform something similar in other occasions and we also have to consider that there is another feat which can be scaled to building/large building in the verse so a baseline building level not only isn't a big jump for the character but is not even a big jump for the verse.
Also, this isn't even the right forum for this thread.
From what I read if you want to use a recalculation this is the correct one since the CGMs are supposed to tell which one is more reliable.