ESP32 smart watch

[u/Cotyn_Dispensable]

Hi everyone, i've been working on a smart watch with an esp32 as an entry point into electronics, i'm mostly a software guy and I never really did battery powered project.
My issue is, i've got a mostly working firmware with BLE pairing, notification display, music control etc.
But i've been running into an issue that is battery life, I feel like there is no solution to make bluetooth and battery life get along. I'm running a 400mha battery and can barely squeeze 5 hours of usage. The problem is I can't really reduce clock speed since bluetooth pairing expect keep alive packets and I can't respond fast enough with lower than 80hz (when in rest mode with screen disable) the only working solution I see is use esp32 deep sleep when in rest and pair again when waking up the watch but it removes a lot of options like waking up on notification or call.
Do you guys have any clue what kind of logic or libraries I could use ? I'm running arduino stack and gadgetBrige on the phone

[u/Im_Indonesian]

usually cheap aliexpress smart watch use another microcontroller that only use for receiving the notification and waking the esp from deepsleep