Is it ever too early to start working on your product's messaging/tone/voice?
Do you feel like you need to get through the validation phase first before you start working on these things? Or do you start with it right away? And if you do, how do you go about it?
Your Tone of Voice must gel with your target audience. Always check who your potential customers are, and align your ToV based on that. I'd apply this rule at every stage of product development.