Cool project!

A ton of aesthetic effort for a simple Dev board + enclosure and a vibe coding project, especially since arduino already has libraries for MQTT, speakers, etc… Photo displays & animations galore lol.

Injection molding is much more of an art than simply CNCing a negative of your part and squirting some plastic in it. There is a reason that injection molding services often have around a 1000€ startup & molding fee.

Plus a custom PCB means FCC/CE certification generally.