One piece blanks

Spigot ferrules? They still have an insert so they are thicker than the rest of the blank (flat spot). Rods with tip over butt ferrules are built in pieces on different mandrels. As far as I know the mandrels are the same. If there is a rod you like you could contact the manufacturer about making it one piece. They would need to design a cut sheet for the carbon fiber so it could be rolled on one mandrel. Chances are they won't do it for one blank but if you get enough people together they might.
Was (still am) looking into one piece blanks myself, I found this info on the stripers online forum.

Originally Posted by midwestexile

Does anyone throw with or make one-piece fly rods? What blanks are out there?

CTS makes a 1pc blank in almost every imaginable length and weight. But getting them into the US is a pain in the arse.

Rogue makes a 1pc, a 7'9" 8/9/10 and a 10/11/12wt.

Eddie and Kenny at Biscayne rod have their "Billy Baroo" 1pc. I've asked before and they said the blanks were available.

There are still quite a few of the old Fisher graphites around too.

Loomis has no plans on making their Pro1 blanks available for rod builders. And that's fine by me."
I have used Talon before, they will custom make a blank for you.
To this day my all-time favorite rod is one of their blanks.
Great people to work with, and from the state of WA, so you are supporting someone local. Let me know if you need more info.
Just an idea.....