Here is a great device on the Adafruit blog, which could be interesting for all day activity tracking:
https://blog.adafruit.com/2018/05/14/biohacking-all-day-eeg-recording-tools/
with EEG recordings during activities, you have to consider, that there are movement artifacts. Even recordings at rest are full of artifacts, as Arnaud Delorme has been demonstrating with in his video series, where he recorded Muse data with the Mind Monitor app, and removed those with EEGLAB.
Soterix Medical also has found a solution for a artifacts removal from EEG recordings:
6.3.22
SMARTING
mobi
portable EEG device:
https://mbraintrain.com/smarting-mobi/
6.3.22
Arnaud Delorme – EEGLAB tools for mobile brain imaging