Have you played this game? Luigi's down-b will be enough to get him onto the platform in most cases. There's no such thing as unnecessary stalling. Why do you have such an issue with it? Sure it's boring to watch, but what is it that makes it anti-competitive? Let me rephrase it... matches are far more likely to go to time on PS1 than on PTAD. Even if there were more stalling time on PTAD, the nature of the stage forces combat a lot more than PS1 does.
Large blastzones are not only "not over-powered". They aren't even a bad feature of a stage. They are a counterpick quality. You say we ban stages for "over-centralizing or skill-marginalizing elements". Which one of those does it fall under?
No, your Mario Bros argument is not a valid comparison. It is much more reasonable to expect a player to avoid the cars than it is to expect them not to get hit by a turtle shell. I suspect you haven't played on PTAD seriously very often if you have such an issue with the cars. I know saying "it is much more reasonable" is subjective, but it should be obvious in this case.
I forgot about Luigi's Down B, I was only thinking of Up B's at the time.
If stalling isn't anti-competitive, then why do people want Planking banned?
Like I said before, you can't make claims about PS1 being more likely to go to time than PTAD, you need evidence. I am willing to get some to help my case, but only if I know it will be worth it.
Large blast-zones falls under "over-centralizing", but is only a minor example of such. Like I said, if enough small elements of a stage are put together, it can make a big difference. While the blast-zones weren't a reason to ban the stage, they were support for my main argument on the cars.
But what if an opponent knocks you into a turtle shell? Do you feel it is fair you died at a low percentage and just got "out-played" by your opponent. I have played on Port Town Aero Dive seriously, and each time my opponents and I have abused the cars and poor recovery (thanks to the edges) to get ridiculous kills on each other which took no skill at all to achieve.
PTAD should stay banned because gameplay is over-centralized on avoiding the cars, this can lead to long periods of stalling which is detrimental to competitive gameplay.
The un-grabbable ledges force players who aren't using 1/3 (if that) of the cast to get damaged (several times in some cases) to recover, and in other cases just fall to their deaths. It also takes out any skill revolving around ledges like edge-guarding and hogging.
Overall, the gameplay on the stage would play out like this: Normal battle on a small amount of the transformations, camping on the transformations with cars, and getting gimpy kills on the transformations with the ledge-less platform.