I've seen plenty of wood from Bangladesh, Majority coming from Sylhet , Hill Tract , and upper Bangladesh Jaflong areas also. Majority of the plantation wood is hammered with Steel nails and left for numerous years , one thing I do is try to slice the piece with a hole and you will see the redish brownish rust kinda of color around the infection , then you know that steel nails were used, it's still burnable , some people clean out redish part if there is any , if not than holes were drilled and left , & sometimes they wrap the tress with barb wire , you might see injection laden wood also but not that much , the nail laden trees scent profile I noticed is like sweet molasses type and slight spiciness & should be burned on a low heat, yes you are correct that wood tends burn out like Wooden amber red , but I have smelled Wild Bengal Aggarwood that has more animalic profiles that bubbles intensely and super spicy , there are trees in Sylhet that have natural infection over 150 years but are very rare & usually reserved by people in the GCC countries so almost impossible to get ( the people of Sylhet used to Worship the trees till Shajalal Al Yemeni came down and spread Islam , there are old trees from that time but are not touched around where Shajalal is buried ) , there are Wild Trees in the Chittagong Forest and protected by the military , they have shoot to kill policy. There is a Amusement park that's right beside the Chittagong National forest and there is a boat tour and you can see the Aggartrees on the mountain side , they look like giants , & there is lots of Wild Trees in Jaflong area , the people of that area worship the agar trees , there religion also based on Animism , Hence they protect it , you can find certain Villagers that take shaving from the tree for medicine and selling to certain people , they rarely sell the wood If they do it's for the villagers to help them out , & wild Trees are all over Bangladesh but people have no Idea that its Aggarwood.
Best thing is if you visit Bangladesh and there are many Attar stores that sell wood , the best store I can refer is Al Musk , located in Bashundhara City Mall , Level1 Block C shop # 3 , when you walk in the store it looks like a Jewelry & clothing store but go in the back you will see all the aggarwood in display and they have 15 types of wood , and you can test on the spot , plus there Oud Oils are great ranging from Sylhet and Burma and Cambodi , and they have higher Grade oils only for there Special Arab Customers ( Typical Bengali can't afford oud , 1 bottle is like 2 years of Income ) Hence Majority are Arab and Tablighs who travel to Bangladesh tend to get there Oils and wood ) , Al Musk has multiple stores in Bangladesh and Every time they open a new store Al Haramain Opens right beside them , lol , I advise to walk in Al Musk instead of Al Haramain ,
The Grade of Wood looks like Ok but its plantation wood so people would Say C but it depends on your taste , If you smelled Woods From E.O or Adam you will see the difference in profile range & would probably give a Bad grade , but I would say the Woods Ok , just burn it on super low heat if possible to capture the nuances