If you use a scale and mix up a liquid batch, you can dose mls more accurately.

But the difference between a tank that has say +/- 2ppm of NO3 over a 5-10ppm range and another that has a error of +/- 0.5ppm is not going to influence a tank.

It potenitally, however, I've yet to see any evidence of it, could be an issue if you dose nano's, as getting th eincrements small enough for teaspoons is tougher for 3 gal vs a 100 gallon tank.

Still, I've kept 8 nano's for the last 3 years without any issues doing it dry.

So............the issue is not real near as I can see.

But some like doing it this way and prefer that over dry powder.
I'd suggest using KNO3 , KH2PO4 and TRaces is seperate bottles and dosing from there. A GH booster bottle is optional if you need GH and a little more K+.

Some add the KH2PO4/KNO3 together.
Really up to you.

Some fine it easier to dose every day vs 3 time a week.
Just take the week's totals, divide by seven instead of three.

Simple enough.

Regards,
Tom Barr