Carbing beers

I am trying to get better at carbing beers and am looking for pointers. I bottle and keg. The last time I bottled I used carbonation drops. 2 drops in 750ml bottles and the beers are great, I would probably do 3 drops if I wanted a very high carbonated beer.
In the past I have added priming sugar into a bottling bucket and xfered the beer and then xfered again with a bottling wand. I feel like the consistency of carbed beers done by this method is not as good as the drops. I have tried stirring the bottling bucket, adding the sugar in the beginning and middle of the first xfer, etc.
I think I will be using drops from here on out, any comments?
Secondly, Kegging. Where i would like he most help.
I do not have an exact science for achieving proper volumes of CO2 in my kegs. I have read pages like this,

Looked at charts etc.
Typically when I carbonate I beer I set my regulator to around 22psi. Right now it’s at 27 because he Aussie sparkling I just put on says high to very high carbonation. I leave 5e beer at this pressure for a few days. Then I purge my keg and reset the psi to around 8 for pouring.
My CO2 line rises up about 30 inches to a manifold and the lines drop down 12-18 inches to my 3 kegs. The bottom CO2 line is 2 feet, the top is 3 feet long because it has to travel further. All of my liquid lines rise 18 inches to the faucets and all the lines are 8’ 3/16”ID beverage lines.
Can anyone recommend anything to me about keg carbing beers? Or comment on my lines or method?
Everything works, looking for pointers.

For all things related to draft beer, including balancing your system, length of lines, carbonation vs. psi, elevation, etc., a great reference is the Deaught Beer Quality Manual which you can download from the Brewers Association website.

I know. I’ve skimmed part of it before. The system works, I would like to be better at it I suppose. Sometimes technicals go above my head I.e. I not exactly sure what to trouble shoot or where to begin, if there is a certain spot to begin.

I usually base my carbonation off of a few indicators, mouthfeel, head retention, bubbles on the side of glass and the duration.

I’m not really sure how to calculate CO2 volumes. I just pump it in and drink.