You can turn it off, it has no effect on the phone, but it charges faster if you turn it off.
Try to turn off wifi, games and other programs when charging.
If you want to charge quickly, you must turn off all the programs in the phone, including wifi, mobile data, etc., which can improve the charging speed. Or put your phone on airplane mode to speed up charging.
When charging the mobile phone, it is best to open the battery doctor software, so that it can be more safe and effective charging, while recording your charging habits and reminding you to correct bad charging methods.
Enabling the WiFi function while charging the phone has no impact on the performance of the phone and can be used normally