It’s safe to do so, but functionality will be affected. Dimmers work by changing the voltage waveform applied to a load which, for compatible products, results in the reduced light output. If the voltage waveform applied to the smart downlight is altered, the downlight can no longer achieve maximum brightness. If the brightness level is then adjusted in the app, the actual brightness will be less than the maximum brightness that can be achieved. Mercator Ikuü does include a dimmer wall plate and in-line dimmer switch should you desire a Mercator Ikuü compatible dimmer switch.