No!

Excess nitrogen will inhibit flowering at this point.

Gotta decide what's important here.
Pretty, green leaf, or active ingredients.

It is normal for a maturing plant to raid the fan leaves to make flowers.
The big fans have 2 jobs.
They support the vertical growth of their node.
And they store energy.

When vertical growth has ceased, and flowers start to swell the plants energy needs triple.
The plant no longer needs vertical growth energy then.
If the root ball is marginal, the plant will use that stored fan-leaf energy to flower, and the fans will yellow, form an abscission layer and drop to the ground.
It's a natural process. and you need not be alarmed.

You can keep them prettier, longer, if you transplant to a larger pot when you put them in flower.
And yes they do grow beaucoup roots in the first weeks of flowering, I have watched it in my dwc grows.

The good news?
Your plants are "trimming" their own buds for you and your harvest work is half done.

Aloha,
Weezard