Unfortunately I have not been able to track down the cause of my 4.4.4 battery drain so far. As soon as I switch my primary FP1 back to Macadamia, it gets 2-3 times the mileage (read: the battery lasts 2-3 times as long). I have switched back and forth twice now, same pattern each time.
4.4.4 vs. Macadamia:
To make things further complicated, my secondary FP1 does not show any difference between 4.4.4 and Macadamia with regard to battery time – this secondary phone is just lying inactive (airplane mode) on the shelf though.
Now gradually trying to switch all secondary FP1’s settings to my primary FP1’s settings, step by step, in the hope to narrow down which function/setting/app lets my primary FP1 drain so much quicker under 4.4.4 than under Macadamia.