Stuck on BVA after 476, can't apply for 500 onshore - spouse's subsequent visa is pending

I arrived in Australia in mid-2024 on a 476 visa, which was valid for 1.5 years. My current wife wasn't listed on my initial application as we weren't married then, even though we got engaged a while before I came over. She joined me in September 2025 on a 1-year student visa. We got married a couple of months later and have been living together since December. My 476 visa was due to expire in January 2026. Before it did, we applied for a subsequent entrant visa for my wife. I'm currently on a Bridging Visa A, and the application status for her remains "Received" in my ImmiAccount. I secured a PhD scholarship in February and tried to apply for a student visa (subclass 500). However, the system blocked me, saying I couldn't apply onshore because I'm not on a substantive visa, due to "visa hopping" rules. I've had to push my PhD course start date multiple times, now to late June, while waiting for her visa. We've submitted a ton of documents - marriage certificate, joint finances, living arrangements, you name it. I also updated DHA about my change in circumstances, providing my CoE, scholarship details, and new OSHC. I even uploaded an expedition request with a formal letter from my supervisor and called DHA twice, but there's been no movement. I'm incredibly stressed about this. My main question is, would applying for a Bridging Visa B, leaving Australia, and then applying for my student visa (subclass 500) from offshore be a viable option, or would it just add more risk? My wife's student visa expires in November, and I'm losing hope. I can defer my studies again, but her visa deadline is looming. Any advice or suggestions would be hugely appreciated!