It will behave more like an autoflower - it will stay small because it's getting 6 hours less light than usual for a photoperiod, and then it will start to flower on its own accord, usually around week 4 (depending on environment and genetics). It's not an uncommon technique if you want to do SOG from seed. More costly on the initial investment as you need more seeds to fill a tent, but will save you money on electric running 12/12, so pros and cons.
Good luck!