When I was younger I wanted to move in to management type roles. However I have never had (or made?) the opportunity so I feel like these are outside of my short to medium term goals. Moving to a company that offers advancement would be an ideal, but in the meantime I feel like I need to make myself a compelling candidate.

I totally understand around difference between pm/dev work though - in a perfect world I want dev work, however I am willing to accept it's not a possibility for me at my age whilst maintaining my current income.

I don't have a technical network for job opportunities (due to non technical teams) and job ads/recruiters seem to filter on technical proficiency.

Another commenter said I should double down on basics and meet end user needs - that's precisely what I do. I get things done, but can I demonstrate technical knowledge or professional experience with language x? Can I define what a singleton is? I'm not so sure.

I want to reiterate the earlier commenter's words: focus. You seem to be spread thin amongst various roles in a typical software/tech company, from product manager/scrum master to developer. Hone your attention to what you really want and if you aren't sure, then start anywhere. You won't know until you try!

I'm not sure if LinkedIn is big in Australia but recruiters in America will scramble to you with offers for possible jobs if you update your profile with the latest tech and frameworks. Your non-standard background definitely will attract interest so give it a go.