309 Offshore Partner Visa Timeline & Using a 600 Visitor Visa While Waiting?

I'm hoping for some insights on my offshore Partner Visa (Subclass 309) timeline and a potential relocation strategy. My partner is an Australian citizen, and I'm from a low-risk country, with very strong evidence of our long-term de facto relationship. We lodged our application on May 18, 2026, and I completed my medical checks and uploaded them in July 2026. I'm currently just waiting for the official letter to apply for my police check, which is the last main document. Our lease ends and employment contracts finish by mid-June 2027, so we're aiming to move by June 1, 2027. My main question is about the realistic processing time. By June 2027, it will be 12.5 months since lodgement. Given our robust application and low-risk profile, what are the chances of getting the 309 granted by then? Or is it more realistic to expect it to take closer to 14-16 months, based on current trends people are seeing? Secondly, if June 1, 2027 arrives and the 309 is still pending, I'm considering entering Australia on a Subclass 600 Visitor Visa. Since the 309 can now be granted onshore, my plan B is to wait in Australia, accepting I won't have work rights initially. Has anyone recently done this? Did you face any issues at the border regarding the genuine temporary stay requirement, or did having a pending 309 make the entry smoother because the long-term intent is already clear? Any advice or recent timelines from others, especially those who entered on a visitor visa while waiting, would be greatly appreciated!