the implementation of PlayerBasedCastingEnvironment is caster.sendMessage so that wont change much
the Circle based one just prints to it's impetus

@walksanatora can you expand a bit more on why this is necessary / a good idea, and how much effort it would be?

In terms of how good it would be. It would be nice to standardize the sending if feedback. This also means that non-player casting events that log stuff (eg: mishaps/other spells/actions that have chat output/warnings) all can be handled by the environment

the biggest offender of this iirc (from my scan through while making #590 ) was the mishaps