I think you are catching this all wrong pal.
It's not 650g per plant.
It's 650g per square meter..
Most you I've seen from a 15 weeks grow is 150+g 110 from an auto. And they're few and far between.
Tbh with you. I'd focus not on yields. But, getting 101s down is essential. As if you don't do the basics right. You'll never even hit a 100g per plant.
Weed indoors doesn't grow like that.
Do a few grows. Stop looking at yields etc. Look at DLI, good nutrients, good light and environment. Everything after this will fall into place after a few grows.