When I was an apprentice, I worked on my "master's" instruments, and had to bend the linings this way, because that's how he wanted them. I did this on violins, violas and cellos. Bending and gluing in linings this way is extremely easy and fast, I really liked it. I don't bend linings on my own instruments this way, despite doing it this other way so much in the past. This is for no other reason than I want to conform with the majority, but bending continuous linings work really well. The ribs were bent on an inside mould always in that workshop.
Ok! And of course it is a valid method. But if you glue the linings continuously on both sides of an inside mould, how do you manage to pop it off the mould? And often when I've seen violins with continuos linings, there are little triangular gaps in the transitions from block to upper and lower bout ribs, because this line isn't quite as hourglass shaped as we like to think. There's actually an angle in the inside shape on most models, unless one fills it up with a very large block shape. It is very natural to do this in a naturally hourglass shaped instrument like the guitar, but at least the classical violin models, really aren't!