BDR to AE jump...when to stay and when to leave for a promotion?

I joined a late stage startup in 2019 as a BDR to get my foot in the door for tech sales. I was the top performer on my team in 2020 with the most qualified meetings, $12M in qualified pipeline, and over $3.5M in closed won deals that I sourced. I would really like to stay at the company and have done everything proactively to make it known I want to move into the next role such as seeking sales leadership mentoring, co-running deals until closed won, and even running first and second meetings and pressure testing deals to see if they are real until an AE takes over. I interviewed for an AE role and was told “I need more practice.” There has never been a BDR promoted at the company. The last 4 BDR’s left and found AE roles at other companies that I wouldn’t say are as high of caliber. There is a promise to get me more practice but I don’t know if I believe it. I don’t want to restart as a BDR at a new company. Would my best bet to wait and see or should I look outside the company to see if there is someone who will take the chance on me and offer mentoring for any gaps I may have or should I wait and see and hope for an opportunity at my current company who has a bad track record at promotion and is on track to IPO in about a year or so.