A friend of mine did a similar thing. They vegged for only a few weeks, then flowered and had a dramatically low yield.
When the plant is still lateral branching it is not sexually mature. Once there is only one branch to each node, the plant will produce a LOT more.
Lateral branching
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Sexual mature
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The plant does look very happy, but you might not be after the time, money, and effort it takes to grow decent bud.