Customer, when running an induction hob on low (simmering), notices the load fluctuating between 300 & 1400W.
We know this occures when using the hob thermostat as opposed to W setting. The question, will these quick fluctuations cause premature aging of the Multi.
With quickly changing conditions, of course, the stress is bigger for all things.
So, in theory no, as long as the components are properly sized.
In reality a lot of factors could influence the outcome: components used and their quality, manufacturing process and control, tolerances, etc.
Use the product as intended and enjoy the warranty if this is the case. 