If you're talking about length and this is a new form of your own design then I would say it's a trial and error thing because you don't know how they will bend due to the taper rates and the degree of curve. I suggest using washers or any kind of centering devise like that. Looks like you have about an inch or two to spare. Looks good. With that amount of deflex you should be able to have some good long hooks maybe. I bet you end up shortening it 1 to 1.5 inches from what you have in the pics. No standards, looks like you have working curves so it’s going to be kind of like tuning an arrow by shortening it. I would mark the center line and cut a wide (margin for error) taper profile. Make some of those washers with slots and use a bowyers knot for adjustability and try to brace it with them. I've seen guys use a peg board to brace the bow with the washers, some have the pegs attached to the legs of their work bench (sounds scary, be careful). Keep trimming the length until it is stable enough laterally then put some tips overlays on and finish it.