I dont understand why people think pure sine wave inverters are inherently better than modified sine wave, except when directly driving AC motors for long periods of time. π
Most devices nowadays are DC powered via a wall wort or charger, and the bridge rectifier in the switch mode power supply ain’t going to give a damn what the sine wave looks like. If you are worried about inductive spikes when the output transistor turns on an off on a modified sine wave inverter, just plug it into an inexpensive surge protector and the varistor will pass any spikes to ground.