I myself did get some thick wild old coppice hazel, some was near 4 inch diameter.
I'd say it was average as fuel, it makes good kinderling with the draw knife shavings, burns hot and cleanly and creates a burst of fast heat to get the bigger logs going. As with any fire wood it needs to be dry, 20% moisture content or less. I'd say get some its not like felling standard oaks or ash trees, the poles are light enough to carry about without a skidder or horse, I once carried a ton or so on my astra roof rack
NOT recomended 35mph up the a140
. Do you have a trailer? Or borrow one? Pile it full up heaped right up sling a tarp sheet and straps over it. You can get the poles just with a sandvik bow saw, minimal mess and noise low impact no need for a chain saw crosscut them into 8 foot lengths or to suit your trailer etc. When you cut the poles make the cut close to the ground and sloping away from the centre of the stool clump so water runs off. AND the most important thing, the stools will recover and next season (sproingtime) they will have a cluster of new shoots that will deveopl into new pole's real fast. I wouldnt be cutting hazel right now though, I'd wait until next autmun/winter. If the poles are thin I wouldnt get them for fuel, theyd be better used for making hurdles or something