Re: relactation and hand expressing
Hand expression is generally much less effective than pumping at removing milk. If you want to continue to increase supply via hand expression alone, you are going to have to work HARD at it. That means removing as much milk as possible as often as possible until you meet your goals. Feeling "full" after hand expressing probably does indicate that you have left milk in the breast, and that is definitely counterproductive.
I personally would continue to use the PIS or rent a hospital-grade pump. Yes, using a pump may mean "wasting" milk that clings to the sides of the collection tube... But you want to focus on your long term goal of increasing supply over your short term goal of collecting every possible drop. If you waste a drop now but in the end you have oz to spare, that beats saving every drop now and ending up not increasing supply as fast as you might be able to when using the pump.
I suggest seeing a lactation consultant for pumping tips and to make sure your shields are a good fit. That can help you maximize output with the pump. And if hand expression is working for you, keep doing it! You can combine pumping and hand expression and thereby get even more milk than you would with just one of those options alone.
Coolest thing my big girl said recently: "How can you tell the world is moving when you are standing on it?"
Coolest thing my little girl sang recently: "I love dat one-two pupples!"