Two Mast Splices ?

[Brion Toss]

Hello,
Although two splices will put some extra weight in, there's nothing structurally problematic. In fact, careful placement following mind-numbing calculations might even allow you a somewhat smaller section. But just focus on generous overlap and tapered ends for the interior pieces. See if you can avoid having a splice at the spreaders, as it makes mounting hardware difficult. Keep the other splice low, for weight.
Fair leads,
Brion Toss