Congrats on passing the SIE. The SIE is not an applied exam whereas the Series 63 is more application. It is shorter in length so you will want to focus on being able to complete the practice tests with plenty of time left over to ensure you are building the stamina and ability to get through the entire test with some time to spare. This will help you during the real exam and prevent panic or rushing.
Focus on tying the material together. If I had to do it again, I may have supplemented my preparation with test prep material from other sources as well to get better exposure because the real test for me had very different wording than what I saw in the Achievable practice exams.
Do as many practice questions and re-read the material as you get closer to the test. I studied for almost 3 additional hours on the day of my exam so I could recall information.
The last week before the exam is critical because the pressure of the deadline will push you. Even though according to the metrics I was well prepared, the real exam is designed to make you feel like you are failing but you have to rely on your ability to recall information, tie the concepts together and apply test taking strategies such as eliminating wrong answers, filtering unnecessary information from questions and reading questions quickly. Speed is the name of the game since there is time pressure. In the Achievable material, they say that the exam is nitpicky and I agree with that sentence because I saw questions where you can eliminate 2 out of the 4 multiple choice answers but you have to choose the BEST option out of the remaining 2 and you may have to re-read the question to focus on what is being asked of you. Ethics and registration made up the bulk of the test for me. I didn’t see any questions which required me to calculate - such as when assignment occurs or shortfall coverage.
Hope this helps.