Is capacitor leakage harmful? Polymer current leakage compared to electrolyte leakage
Your residual current circuit breaker is only measuring leakage currents from the supply (phase/hot/live) to ground (Earth).  It doesn't measure any other leakage currents in your application.

So if you are putting suppression capacitors between the supply and ground, then leakage matters.  If it's within the DC part of some controller electronics, then it doesn't matter to the circuit breaker.