Hi there Mhp, Welcome to the forum.
While your suggestion is a sensible one hard rock gold is a very different & expensive one compared to panning, sluice boxing or dredging for alluvial gold. The Coro isnt known for its alluvial gold although there were a few areas that were worked by ground sluicing that recovered dentritic, eluvial & residual deposits of gold that had eroded & broken away from outcropping vein & load material. Once the overburden was washed away it exposed these often very rich vein stringers & loads. This of course then lead to hard rock mining which is sort of outside the fun & hobby side of fossicking for alluvial gold.
Hard rock mining is a way more serious & expensive side compared to hanging out in the beauty of a Coromandel creek gathering a few, if your lucky, specks of gold that you can see & take home with you without any further proccessing.
I doubt that the tree hugging frog arse licking greenie type that ooze out from under every rock & from behind every tree in then Coro would appreciate a group attack on one of their creeks turning it over in search of some alluvial gold. Like wise I dont think DOC would be too happy about it as well. As a single person having a quiet pan or sluice box they may well turn a blind eye....unless of course it is muddying up some "locals" favourite swimming hole.....
As forum members are from all over the country you would need a few claims throughout the country so that people didnt have to travel miles or from one island to another with all the costs involved. The south island is by far the more sensible choice due to the wide spread deposits of alluvial gold & a more friendly approach to alluvial mining. Although many creeks, worth while or not, are now all claimed up with dredging claims.
The hobby side of fossicking for gold is not the focus of making money from it but just for the enjoyment of doing it. The beautiful places it takes you to & the like minded people you meet, & to be happy with maybe a little bit of colour for your effort.
Good luck out there
JW :)