Around here in Australia Narra is the common name used when it is not in Burl form then Amboyna Burl, two main types or definitions Golden and Red with a multitude in between. It covers so many Rosewoods and grows in many countries.
Your sample pictured initially perfectly covers the common definition used by suppliers can have wild grain, do never feel put down by your piece when you finish turning and apply a finish what you have is astonishing in its detail, look forward to a finished product.
I am reminded of the Aussie Movie Crocodile Dundee when Paul Hogan flashes that large Bowie knife and says thats a knife. Size and excess are meaning less as you will find with your pen or whatever from that board it will be judged for itself. I have a board or two of NARRA with excessive wildness similar to yours I cherish. What happenned to me was a Brisbane guy spent a year in the jungles of an Island nearby Australia called Vanuatu and ended up with a shipping container of Golden Amboyna cut for Billiard Cues a buyer in Canada received most of it welched on the deal said rubbish refused to pay said send more.
Well I got the balance of that lot and shared it on another forum at my cost only.
New Guinea Rosewood , Narra when normal Amboyna when Burled can be spectacular as well.
If you send me a pm I will post some pics to illustrate Golden Amboyna however I emphasise your board is spectacular, wild and special.
Kind Regards Peter.