Dont see why you couldnt use your led from seedling?
One thing I do advise is raising it slightly higher in the very early stages of seedlings - the leafs tend to twist and warp badly using LEDS.
After around 2 weeks you can lower the LEDS.
Also you should probably lower the power of the LED unit if you can, I think its wastefull running LEDS at full power in early stages of veg as the plant will only grow as fast as it can.