Pro tip: stop gluing the spine before you round it, I learned this the hard way on a 400 page rebind
I run a small shop in Boise and picked up a rebind job for a guy's grandfather's Bible, 400 pages, super thin paper. First three attempts I glued the spine flat, then tried to round and back it. Every single time the glue cracked at the shoulder, and the text block fanned out like a cheap paperback. Then a binder at a meetup in Spokane asked how I was setting the spine and just shook his head. Round and back FIRST, then glue. The shoulders need to hinge on the cords, not on a rock solid slab of PVA. Once I switched the order, the Bible opened flat on the first try. That mistake cost me two cracked spines and about 12 dollars in wasted boards. Anyone else learn a basic step in the wrong order and feel like an idiot later?
Learned this same lesson in a totally different way... I used to frost cakes before they cooled because I was impatient, and they'd slide apart every time. My grandma watched me do it once and just said "you're building on a warm foundation, sweetheart." Same energy as your glue situation. The order matters more than the effort, and that shows up everywhere, like painting a wall before you patch the holes or laying tile before the floor is level. We all want to jump to the part that feels like progress and skip the boring prep, but the prep IS the work. Glad the Bible came out right in the end, that's a heavy thing to get handed to you.