I thought the length of the rod dictates the location of where the piston will travel. I don't think it dictates the amount of torque or HP an engine will have. Example, if i build a type1 engine and use a 82mm crank and use the stock length rods the piston travel will start further out in the cylinder and travel out the end of the cylinder or crash into the head if it is installed. When stroking an engine the longer you go on the stroke this increased piston travel must be compensated by shorter rods and or shorter pistons. That is why you buy Piston and cylinder kits made to the crank size you are using. The position and length of the cylinder doesn't change so when a crank that increases the length of the up and down piston travel is used things must be changed to compensate, this is accomplished by using short rods and short pistons. At the end of the day the travel of the piston must arrive at or near the top of the cylinder but not past the top of the cylinder. The piston can't travel too far down into the block either. Cylinder base shims are used to fine tune the piston top dead center to set the compression ratio. The other issue on rod length, as the cranks get into the larger stroke lengths (84-86mm) by having a rod that is too long takes the rotational angles into unfavorable territory and it develops high side pressure on the pistons and piston and crank bind. There are rod length and piston height formulas that work the best already figured out by engines builders that came before us, they have made the mistakes so we don't have too. If you call CB and tell them what size engine you want to build they will give you the correct rods and pistons for the crank you choose.
Yes there are those that have made longer than suggested rods work by using big spacers under the cylinder bases to move the cylinders further away from the crank. This is where you get into having the width of the engine increase and the stock cylinder tin has large gaps on each side where the tin should meet the fan shroud. This condition can't be kept from happening to some extent on the super long stroked engines. They sell filler blocks to fix this issue and keep the cooling air from escaping and causing an overheating issue. The need for longer head studs may occur as well. I have built a few engines and have learned this stuff as I went.