Thanks, that is helpful to know. However, a switch-mode power supply is quite different from a reactive load. Cheap ones tend to draw power only near the voltage peaks, whereas better ones improve on that. See [1] and [2]. So the question remains how well these cheap power meters cope with such a nonlinear load.

[1] https://en.wikipedia.org/wiki/Switched-mode_power_supply#Pow...

[2] https://en.wikipedia.org/wiki/Power_factor#Power_factor_corr...