The discussion has gone off on a tad of a tangent ( they usually do ).
I'm not sure what the 15mm kills up to 25 yards and/or the acute angled close shots has actually brought to FT or HFT!
I understand why they crept in, especially HFT. Super accurate expensive target rifles, decent pellets and ( HFT ) a rock steady prone stance with forearm,glove,hand on floor and butt on ground, meant that something had to be done to try and make courses tougher.
I'm no super expert but on the range using a HFT style prone stance and a decent pcp ( not even a super expensive target rifle ) ... and on a calmish day ... hitting 15mm's repeatedly at 25 yards isn't really that difficult. On a good day I'll nail them most of the time with a springer.
I'd imagine it's not really all that difficult either for a decent FT shooter in their sitting stance.
On a day where there is just enough wind to drift the pellet towards a split at 25 yards I can see that there is skill in recognising that wind and aiming off to drop the pellet inside that 15mm.
On days where there is a reasonable wind ... and it's variable ( as wind almost always is ) ... you now get a lottery. If you get a wind where you could literally clamp a pcp in a vice and indoors it would just make a slightly enlarged hole at 25 yards over several shots ... and then you take that set up outside in variable and reasonable wind and you try and release at the same wind speed ... and you are still getting a spread edge to edge of over 15mm ... then skill has now given way to chance.
If you are now talking quite a few ( 7 ish ) of those targets on a course ... and it's lotto time. Some will get lucky ... and some won't.
Look at some of the HFT scores when it's been windy. You will see the odd guy gets a reasonable score ... maybe 55 or above. There will be plenty of top guys on those days who suddenly get awful scores ( a dozen points below what they normally get ). On other similarly windy days those top guys with previous awful scores now get that top score. Have they been bouncing from being a fantastic shot to a dreadful one in a matter of weeks? Probably not. It's probably more to do with their numbers came up on the lottery one week ... but not on another.
The crazy angle shots ... I just don't know what they bring to the game? Shooting skill becomes second to who is the youngest, fittest and most flexible.
Ok, you can say that they are interesting and add a bit of fun. I've watched Masters golf comps on the tele for decades. I can't ever remember seeing part way around the course a putting green with a giant windmill that you have to thread the ball through and avoid the turning sails/blades ... on the other side the ball has to go over several humps before it reaches the hole.
So if adding silly elevation shots, which turn that lane into a Crazy Golf style target is good for the sport ... then carry on.
We've done all this to death to be honest.