Those certifications certainly help you to get a finance job, but not necessary help you to get into any MFE programs.
The objectives of the certification exams and MFE education are different.
Put it that way, a MFE student can probably pass those exams.
But for those certification holders without proper engineering or science background, the MFE materials may be too much for them.
What are those MFE programs looking for is students with solid quant. related education or background, and coding skill.
If you have finance knowledge, it is good, if not, you will learn in those programs.
For sure, if u have a high score on GRE Math sub. test, it will weight more than you have a CFA L1.