Sounds like an excellent idea

They did say necessity was the Mother of invention!
All those BPL blokes could come up with was a joiner that relied on removing the strongest parts of a trekking pole and leaving two pointy ends, from what Iv'e read they also are still a bit stumped by the flicklocks lol... Your way will also add an internal sleeve to the weakest part of the resulting tent pole rather than the strongest... Well done... now for the marketing campaign
Perhaps Aluminium would be strong enough? I found the pole repair sleeve (around 12mm also) for hilleberg poles is the exact diameter of the inside of my Komperdell pole mid sections (so that size alum tube is available)...