If someone made a plugin that needed Spout, don't you think that if they could they would make it not for Spout?
Why would you want that, id advice to use Spout plugin on youre server anyway. It improves the server performance...
I asked myself the same question a few weeks ago. Spyer, which I have used for months, one day decided to require Spout. I looked for alternatives and found VanishNoPacket, which also requires Spout. I just gave in to the trend and installed Spout. It's awesome. I love its teleportation smoothing... AND FREGGIN' CAPES! Just install it; it's not gonna bite.
ALSO the spout plugin doesnt give any lagg at all. Spout is only EXTRA API for plugin developers to work with...