Good job finding something so you can move him around without a person getting bit. Hopefully in time you can find something that doesn't seem to make him more aggressive!
The key is finding out what works for you and your bird. My severe macaw would also lunge at the sick. However, birds tend to want to go up, so I'd always hold the (rather long) stick at an up angle, and over the years, he learned. I had a caique (now deceased) who would fly wherever I told him (so I could get him anywhere I needed to) but he wouldn't step up nicely if he were in a mood. My current caique will always step up nicely on a hand covered in fabric (like a shirt or towel) -- he doesn't even try to bite. My grey always steps up on a stick, even if she attacks it at first.
It's trial and error, especially for the first few years a new bird is in the home, and even after the first few years, they sometimes throw some new and interesting things our way. Keep watching him and figuring out ways to integrate him into the family -- keeping everyone safe and unbitten! Great job! Keep it up!