"Local PNG Landowner Groups subscribed for new IDC shares to be...

"Local PNG Landowner Groups subscribed for new IDC shares to be
quoted on POMSoX"

So if they sold there, what is stopping an ASX broker, from buying those shares on the cheap, and selling the same on the asx to pocket the difference?

I dont know how that works. But we often see other stocks that are held on NYSE, and FTSE also traded on ASX, and when there is a difference there is a catch up mechanism of some kind. (while taking into account Forex rates)