Hi @Orquesm,
It is normal for the back of the PCB to get hot. We use a voltage-regulation component that does its job by dissipating heat.
We’ve had a couple of concerned clients ask about this (Rample gets really hot…), but it is nothing to be scared of.
For the record, we’re thinking about changing this component in later versions of the circuit, for an equally-performing component, that does not get as hot, to avoid this issue of clients getting concerned.