Doesn’t the 90% reduction in the pulse rate of the Eco router cause my wireless devices to increase their transmitting power so that there is an unintended increase in radiation? Similar to how a mobile phone transmits at higher power when the range is poor? In other words, don’t the receiving devices have to ‘work harder’ to maintain the connection, potentially increasing EMFs locally?

No. There is no power control in the 2.4 Gigahertz wifi standard. The transmitting power of wifi clients is fixed and does not depend on the received signal strength. The default setting on all wifi devices is almost always 100% (max. power). Therefore the devices unfortunately always emit wifi radiation at full power, the same as when connected to a non-Eco router. Measurements even show that wifi is the strongest source of electrosmog in modern smartphones. See also 10 tips to reduce electromagnetic radiation from your cell phone and wifi. For some devices with wifi, especially Windows clients with an Intel wifi adapter, it is possible to reduce the transmitting power in Device Manager, but this is also a fixed setting.

The second part of the answer is that the 90% reduced pulse rate of the Eco router does not reduce the transmitted peak power, although the average power is lower. The peak power determines the range of the router, and therefore the signal strength that your wifi devices ‘see’. Only when you reduce the transmitting power of the Eco-router via the settings menu, will the range and received signal strength be reduced, but your wifi devices will still not change their transmitting power, as described above. For more detail see Eco router: 90% reduced pulse frequency.