XC- metric doesn't apply cleanly to your room- you veg in the same space, right?

1g/w/m is the standard for flower room time only- designed to allow comparisons between multi-room grows. Formula doesn't include veg time- assumes that plants of whatever size are moved into flower and immediately or almost immediately flipped.

If you take off all that veg time, your #'s look better.

Also, you're in an artificial situation that reduces plant #'s- if you'd done , say , 30, veged the same amount of time, and then flowered, your weight yeild would have been a LOT higher. ( Your room would also have been crazy crowded)

Recap- 1g/w/m standard doesn't apply to the style of grow that you're involved in- You have VERY GOOD REASONS to do it the way you do, but your style isn't appropriate for a commercial production room.