As you already know, you'll face an uphill battle if you try to apply now. That does NOT mean that it's impossible, but, all things being equal, your odds probably are going to be a little worse at this point. The bigger challenge for you, especially for Haas, is that its Round 3 deadline is January 30 (tomorrow!), so you're too late for that school.
Meanwhile, Stanford's and UCLA's MBA admissions deadlines aren't until early April. So, you have more than two months to pull together strong applications for those schools.
I don't think it is "dangerous" for you to apply to those two schools in Round 3, but just know that they will probably only fill their class with approximately 10% - 15% of Round 3 applicants. Of course, there are a lot fewer applicats in R3 vs. the other two rounds, so your odds aren't necessarily much worse. But, you will really need to stand out to grab one of those last remaining seats in those programs.
I can't give you any more advice specific to your case since I know so little about you, but that is how you should think about the "Round 3 or not Round 3?" question.
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