STEM Master of Finance (MFin) with 6.6 GPA (UQ) | How to bridge the Math Gap for the Programs?

Background:

• University: University of Queensland (Go8, Australia).
• Major: Double Major in Finance and Accounting.
• GPA: 6.6 / 7.0 (High Distinction equivalent).
• Technical Skills: Proficient in R
• Math Coursework: Statistics and Applied Econometrics only.
• Passed CFA level 1

Career Goals:

• Market-side roles (BB Trading or Quantamental HFs) in the US or UK preferably US.
• STEM-designated MFin is mandatory for the 3-year STEM OPT (for US placement).

Questions for the Community:

1. The "How": For those who came from a non-STEM business background and are now in Quant/Market-side roles, how did you actually get the position? Did you do a Master's first, or did you find a "backdoor" into these roles despite the math gap?
2. Online Credit Validity: Do top-tier STEM MFin/MSF programs (e.g., MIT, Columbia, Princeton) actually accept online credit-bearing math courses (e.g., Baruch Pre-MFE, UC Berkeley/UCLA Extension) to satisfy their math prerequisites?
3. The Strategy: Given my math "behind" (lack of coursework, not lack of ability), should I give up on the Quant/Market goal and pivot to IBD, where the intake is larger and less math-dependent? Or is the 1-year "bridge" to catch up on math for a Market-side role a viable ROI?

I apologize if some of these questions stem from a lack of deep research on my part, as I am still navigating the early stages of this pivot. I would be incredibly grateful for any insights, advice, or even "brutally honest" criticism you can offer.

Thank you in advance for your time!