> Making it a requirement is basically out of question

Why? If there’s the political will, it is doable. There are Australian gun manufacturers (e.g. Lithgow Arms, owned by Thales)-and if none of them are willing to cooperate, the government can always start their own gun manufacturer. Indeed, Lithgow Arms was founded in 1912 as a government-owned arms manufacturer, and remained in public hands until the Australian federal government sold it to Thales in 2006.

Same reasons as why things like Clipper Chips isn't happening. It completely lacks technical basis, and even political consensus gets sketchy quick.

Post-war Commonwealth nations are generally bad at gun designs as well - UK tried once and produced an infantry rifle that will(not could) seriously injure its user if held and fired in left hand. So even if forced, the approved gun will be more of a theoretical product, and the smart gun mandate will just be a less politically viable alternative to total firearms ban.