Either way, I'm going to brine it on the next go.
Try the (wet) brine on your second try with poultry, but on the third time, try a dry brine.
With a wet brine, I recommend starting out with a 0.75% w/w (my preferred taste) solution overall, with your total volume of water including the water weight of the chicken flesh (assume 75% of the flesh is water). This is what's known as an equilibrium brine because you are putting in enough salt so that when equilibrium concentration is reached throughout the chicken, you are at your desired saltiness. This is handy because you don't have to worry about how long to brine something, and in fact with an equilibrium brine you should let it brine for at least 6-8 hours depending on the dimensions of the thickest part of the meat.
e.g. if you are brining 2 kg of chicken breast in a topped-up 5 kg bucket, you would need 33.75 grams of salt.
With a dry brine, I would start with 0.75% w/w salt based on the water weight of the flesh, and salt evenly on both sides of the meat and allow to rest in the fridge at least overnight. If done properly, there should be very little exuded moisture under the meat.
Important: if you SV meat but don't plan to eat it right away, salt it prior to final prep, not prior to SV. The meat "cures" over time with the salt and a lot of people don't like this texture.