fph
My opinion,
The Issue
My concern would be the heavier battery draw + extra heat that comes with it degrading the battery. Something is very wrong like the 4Hz cell polling issue or the GPS taking up battery. If I don't have a workaround, 200% battery draw can't be fixed by several changes that add up to a 5% savings. This would now be 195% battery draw--not reasonable. (100% battery draw being the baseline or "normal" for a phone)
Possible Options
(After first testing: GPS off, airplane mode, and seeing if apps in owner, PS, or other profiles eat up the battery.)
1) I'd see if 2026040800 or 2026040801 fixed my battery issue. These look like the relevant google fixes.
update Pixel firmware, driver libraries, HALs and other components backported from Android 16 QPR3 from the initial March 2026 release to the April 2026 release (CP1A.260405.005)
2) Go to 'developer options' to privately send a "bug report" zip file to a GOS moderator and say I have heavy power draw along with other context (e.g. disabling GPS changes it from 100>20% in a work day to 100>60%). And see if they can look into it. (This zip file can have private info like the names of files you saved recently, carrier, location data, etc). However, this'll probably take a while if they look into it.
3) If #1 didn't work and I have a reasonable workaround for the culprit, I might stay with GOS.
For andrej567's situation, I could disable GPS most of the time then I use a charger in the car while using GPS. (But this would be a lot of heat!--heavy workload, charging, and sun rays on the phone)
4) Try re-flashing GOS and see if the issue remains. (not sideloading an OTA. A reflash/reinstall)
5) Or switch back to StockOS.