Cove & bead planks / strips.

Again, scarfing strips for conventional strip planking is meaningless and adds nothing to the structure. If the strips are large and the count per side relatively low, scarfing can be advantageous. Planking like this is more akin to narrow carvel then typical strip planking, so scarfing makes some sense. If the strips are of conventional sizes and reasonably staggered, then the whole area becomes a big finger joint, so no lose of stiffness or strength will be seen.

Scarfing strips is very easy with one of several saws. A simple jig and you can cut dozens of strips at once, all precisely the same, assuming the jig and saw are true.

The only time scarfing becomes a chore is with wider planking or on substantial timbers. In these cases it's best to rough the piece first, then use a jig to machine them precisely. I've used chain saws to rough lapped and locked scarfs in big timbers, then come back with a jig and one of several saws, planes and chisels to clean them up.