Requesting waiver for reference condition in conditional offer. Any experiences?

I just got a conditional offer for a full-time professional practice MPhil. One of the conditions mentioned that I'd have to find a new academic reference to replace my professional reference, since I've only been working for around 2 years and they mentioned on the PAO site that I 'should' nominate 2 academic references if I'd been working for less than 3 years.

I read that bit before applying, but since it was a 'should' and not a 'must', I figured there could be some leeway. Before submitting my application, I emailed PAO to explain my circumstances (been in a job for 2 years, but I was applying to a professional practice program, my job was directly relevant to the program and my professional reference knew me for longer than my academic reference), and PAO replied to let me know that a mix of reference types was fine.

But now I get this condition in my offer. I've already requested for a waiver and forwarded them the previous conversation from months ago, but has anyone else here experienced similar and successfully requested a waiver? I've got no issues getting another academic references, but just wondering if I can avoid it.