For devices where connectivity is more important, switch them from 2.4Ghz to 5Ghz to avoid microwave interference.
(I imagine it's a much lower cost to only handle 2.4GHz?)
The 16 are 4 computers (2 Macs, a Surface Pro 4, and an RPi 4), 3 mobile devices (iPhone, iPad, Apple Watch), 3 media devices (Fire TV, Nintendo Switch, and Kindle Oasis), one smart plug, a Brother printer, 3 smart speakers (Google Home Mini, two Echos), and an EV charger.