It is usually advised to veg untill alternate nodes are present. But at that point, the shorter more compact, the better in regards to light effeciency. The closer the light can be distributed to the entire plant, the more efficient.
2 months that is about 60 days it should def. be in full maturity. you can definetely start flowering now, but it won't be small. during flower it puts on weight. My typical ht. is about 1.5'-2' (40 days and alternating nodes) when I start to flower. My current grow in flower of 3 weeks is already about 3'. That is with training. So it is gonna get bigger when you flower. A lot bigger.