I have never tried hackberry, but I did use a couple chunks of cottonwood once to smoke a Smokette full of trout. It was a very mild smoke without much flavor. Hackberry being so much more dense might be a heavier smoke. If the snow white color is any indication, might also be mild or bland smoke.
Yea, I started carrying the measure stick and gas, oil, and water jugs on it with wrenches in my pockets pulling my pants down when I was real small. Seemed like there was only 2 seasons in them woods, cold and hot. We had portable sawmills with 2 tables each for cutting various type (wetland timber) wood blocks into furniture squares, which they made different colors and grades veneer from. Yep, I soon graduated from carrying stuff through the woods to sawdust shoveler and square stacker, then to skidder driver (favorite part). We also had a huge sawmill close to home for sawing out cypress, cedar, oak, black walnut, cherry, pecan, and other specialty lumber for folks what could afford it. I got smart and joined the USAF soon after high school to get away from all that slaving. Funny how I have fond and humorous memories of it now!
Good to meet someone who knows what it was like!