A small plant, sure. ~50 grams? Depends on efficacy of those diodes. At the very leasat, they didn't skimp on count. 500 at 45w. I'm not familiar with the 2835 chips. Based on similarly sized diodes, probably at minimum near what the OEM's spec sheet tests them at, but just a guess.
30x30 should be fine for your 40x40 tent with good light distribution. Get it as close as possible. Use resulting distnace between new nodes at top to guide you in this regard -- don't want nodes too tight nor stretching out too much. Both stand out. lanky is easy. Tight will look funky relative to fan leaves popping out at nearly the same spot even after it develops a bit. Too intense will eventually significantly stunt growth.