Yes, SK is capable of that.
The technical reason for setting framerate below the V-Sync cap has to do with queuing undisplayed frames, letting V-Sync go up to its full frequency normally lets the CPU start working as many as 3 frames ahead of the GPU and a normal limiter does nothing to try and reduce the length of that queue.
Special K’s limiter with a Waitable SwapChain enabled is always checking how many queued frames are undisplayed and will remove queued frames over time to get the render latency down to 0-1 frames.
At least, that’s how it would work if G-Sync played correctly with latency waitable swapchains. Because they’re not fixed-refresh, there’s no reasonable way of counting the number of queued late frames. It’s better to play with G-Sync off, my limiter’s that good 