Interesting! I have never done that but this may be the perfect opportunity for me to try. You do it just like you would prime bottles, except you rack on top of it in the keg?
I assume if it's done this way, when you're ready to put it in the kegerator you just put it on normal serving pressure since it's already carbed (or mostly carbed)? Thanks brother.
Pretty much, I boil the sugar, add it to the keg, purge with CO2, fill, close, purge, pressurize. You don't have to be ultra-precise as you can adjust the CO2 once it is on tap. Usually I am a little low as it is easier to increase pressure. Yep, just chill and serve (after dumping any yeast that settles at the bottom.