Very few if any devices are so super sensitive to AC waveform quality that a standard generator will cause problems. The main possible example I can think of is something like a ham radio receiver where extra power line noise might cause interference. (Such a unit would also be affected by noise-producing appliances on the same circuit.)
Much of modern electronics are largely immune to power quality issues, as by design switching power supplies don't care too much about the incoming power since they just rectify it to line voltage DC in the input stage.
