I have also recently been through the same steep learning curve you have and the following worked for me. Reading spec sheets is fine but nothing beats measurement if its feasible. I built a custom PCB with all the power pins for all the peripherals broken out so I could put an ammeter in series with each of them individually. Then I used Nordic's inexpensive power profiler kit 2 (search for Nordic PPK2 - its under $100). Really decent specs at 100kHz sampling rate and 100nA resolution - you connect it to a PC to see the charts. I also bought my own resin 3D printer. They are so cheap these days and it helped with iterating on designs and not having to wait days for things to arrive. PS, great post, loved it.