Coming back to the issue: Heatup times should not be a core issue, that prevents one from printing with a decent quality, of course any optimization is very welcome. In my working team, I always ask the team or the PO “Why should we do this project”? Talking everywhere of agile development and value stream, this is a very good “tool” to decide if an optimization or feature is a) good(enough) and b) at the right time (Resources are always limited).
Maybe we should add this question to the template of starting a new feature. At at this point, this question is not completely answered (for me) for the described heating control.