We used to think nothing of going to 6-6 or 6-8 + a little narrower for step-up boards. Of course, that was before Slater was surfing overhead Hawaiian on a 5-8 length.
I'll get you a pic today of my .223. There are several 5'10 or 6'2 blanks made by all of the major manufacturers that will net a nice wide board. One of my favorite though is the Millennium 5'10F. It's a solid 25" wide. Which means you can shape a 23" wide Shortboard or Fish without worrying to much about your offcut.
That which can be assorted without evidence was read in an illegal magazine.
After going to the shop/factory yesterday and talking to two different shapers there I decided to go with the shortboard first for winter/spring then do a smaller fish type board in the spring for summer waves. I picked up a 6'4 Marko Thick (link to pdf specs). I spoke with them in length about the rails/rocker. Still deciding if I want to go 6'2 or 6'4 (blank could be cut to exactly 6'4. Looking at the ci flyer type standard shortboard template 20.5 widthx2.5 (or a touch fatter).
I was planning on buying an electric planer for this board but don't think I need it. Guess I will propably get one next board. FCS2 fins.
TBH I always thought of the Flyer design to be more for day-to-day conditions. As in, day-to-day west coast conditions, which are generally fatter and slower than east coast conditions. That design has a wider tail block and flatter rocker than many of the other shortboard designs. At size, Sebastian Inlet breaks way faster than Trestles or Rincon.
Here's the thing about surfing juicy waves: you're not going to be able to run them down from 50ft away. You need to be in the right spot to begin with and you need to be quick on your feet in the transition. You'll be taking off under the lip, making air drops, and using 100% of the rocker to make the transition in critical conditions. So while you need enough volume to float, paddle speed is actually secondary to timing and judgement and positioning in shorter and quicker conditions. You need to manage the energy, not create it the way you do in smaller and mushier conditions.
My opinion only. I think what McDing was pointing you towards will fill this hole in your quiver better than a more utilitarian design like the Flyer.
Just wanted to post an update: Shaped the blank yesterday. Board is 6'3.25''x20.25x2.75. Nose is 12.75; Tail is 14.25; liters 35.5 according to boardcad. Debating taking the thickness down to 2 5/8. I did it by hand (sandpaper/electric sander) and it took around 3 hrs including setup/cleanup. Never doing another sand job by hand again. Planer has been ordered and on the way. This week i am going to spend my time making future fin jigs as I have decided to go future. Was going to go FCS2 but realized I had an extra set of futures and didn't need to spend $100 on a new set of FCS2. Hoping to do fins at some point this week and glass next weekend/week.