I prefer spring anyway. It's better for the NST season, fans, publicity etc. It could be a very good thing having an accessible mountain of football (P+ advertising working on me) on each weekend with A-League and NST. More football shows covering both leagues, massive highlights and talking points.
We should look to keep adding clubs to the NST that meet criteria, not straight up promotion from below. Build the NST up to a strong competition with the goal of pro/rel with A-League first, not pro/rel with below. This might appease the APL, and it's in their best interests to pump up the NST because some of their clubs will end up there one day.
I've gone through a lot of pyramids, and we don't have to look much further than Japan's for inspiration. Plenty of people have suggested it. Add manually on criteria, grow the leagues, split, grow etc. It will be a fluid work-in-progress for many years to come based on our own strengths. When we have enough depth below, then open it up to NPL (but that's AGES away, unless we have a proper 3rd division as well). I know it's not in the spirit of a fully functional pyramid, but we need to take the baby steps to get there first.
Having the bottom of the NST being a revolving door won't have us moving forward. They need security (like the A-League did), putting more money towards the club and it's facilities instead of throwing money away on trying to survive against relegation with little chance of returning to the NST. Aligning with the A-League and it's season is the way to go IMO, I think the second tier would be more successful this way. I've only just come to this stance tonight hahaha.
The J1 didn't have relegation for it's first 6 seasons. J2 took 14 seasons before relegation came in! In J3 it took 10.