If I counted correct, 4 people reported here phone.apk drain. I'm not going to flash stock, I updated to JDCTeam 6.0 and the bug is gone. As iI said only 5.1 based v6 and v7 has this bug in my case. Basing on that not ever user has it, and changing modem can help we can say that this bug can be limited in some configurations. Anyway as I said after upgrade to 6.0 rom, it is no longer my problem, I just gave you an advice. It is better to investigate it (if it's real bug) and fix because you never know whats more it can affect in future builds and what can happend if one day you'll decide to update modem to another version.
Actually I was able to replicate this issue. I changed my cpu min frequency in stweaks to 486 KHz, and then phone apk had 6% battery usage out of nowhere. It was draining battery. thats the only way I experienced this.
also, perhaps open gapps could be causing this issue, since I used Apr 23 ones. Before that I had april 10 gapps, so it wasnt an issue then.
We can try slim gapps and see how that works?
My issue with this rom is the wifi switching. When I'm on 2.4GHZ frequency, and I move around the house with the phone, then somehow the rom connects to 5GHz frequenct automatically. And it keeps doing this back and forth. This issue exist in CM 12.1 roms. So Dev can you please look into this? The AOSP 6.0.1 rom by JDCT doesn't have this issue. It stays on 2.4GHZ.