When you start TRT without an AI and if E2 increasing: You can feel like TRT is really working then at 6~12 weeks it starts slipping away. That is in part a delay as the -ve effects involve changes in the brain from E2 induced changes in gene expression and subsequent effects on brain patterns. Yes, nipples may create issues sooner.
Your TT, FT and E2 levels are changing between injections. Lab timing changes produce different results - artifacts. If you do not change lab timing, then any changes represent something real that can be used to drive AI dosing changes etc. When guys get T injections every two weeks, their levels have huge swings and then the results are mostly determined by lab timing.