Make sure to check out the thread below if you haven’t already. I actually love the lofting process, but you’re right, there’s a lot of pressure to make the parts in the nesting diagram actually fit on the sheet. A few months ago, I had to make six planks fit onto a 12’ scarfed sheet. I actually worried about it the entire previous night and it actually took some gumption to go into the shop that morning to begin. I kept checking and re-checking the measurements. On the second to last plank, I finally knew they were all going to fit. I ended up having 2" to spare across the 48" I started with. Whew! 
What boat(s) are you interested in? Would love to discuss it over here: