I've had great success feeding miniscule amounts of nutes even a little before flipping to 12/12 - but I wouldn't recommend it. I raise the amount of PK (0-13-14, Bio Nova) from ca. 0,2ml/1litre -> 1ml/1litre but veeeeeery slowly. This way I have got good results. Still, in this case, I think overfeeding is the problem.
Yes that works and you have found something that works for you......Good deal.
Yet many around here have that yellowing problem of too much P&K too early.......MANY nutrient makers list big jumps in their feeding charts and/or their "bloom" feed is too high in P&K to start with....
I say to not start any bloom food till week 3 as an easy and safe way to transition to that "too high P&K bloom food" when the plant is actually more ready for less N and "more" P&K...It is actually the way it should be done.....
I've tried your way and simply found this one easier when using synthetic's.
Some nutrient lines DON'T make a "big" jump at the flip. instead making a small and I do mean small adjustment in P&K and then have you add a PK booster later yet in bloom.
Canna and Hesi are good examples of that.
The real point is that Cannabis does not NEED that (Canna "specific" nutes) to produce quality big buds.....Many of the best growers on the site simple use a powdered 1 part like Jack's or Peter's and kill at their grow.......Dyna Gro Foliage pro is a liquid 1 part that works great and is as easy as it gets.....
Me? I'm back to building water only soils and organic's..
Doc