Light airy buds isn't caused by under fertilizing from my experience. I mean if left unfertilized then of course yes lol.
But airy buds depend on a few factors, strain first. Then usually light distance and or room temperature. Temp fluxuations from dark to light did it for me in the winter.
If your plants are suffering like showing signs lacking nutrients, then it can contribute to airey buds. But if its all healthy. No need to go full bore on ppms right out the gate.
Listen to the plants, and they'll tell you what they need.
I've adapted my feeding routine over the past 4 grows. Not just sticking with one formula start to finish. For many reasons. One being I was going through nutrients like crazy, and I wasn't seeing the yields I wanted.
After some advice and some reading, and of course trial and error. I realized plants only need what they need to thrive, anything more is just overkill and not doing what ya would expect. Boosting at certain stages p and k yes. But driving the nutes to it everyday isnt helping much. Espically those expensive bottles of fertilizer we all use, not matter how cheap, there all over priced.
Advice turned into rant over hhahahah sorry