If you want this to be escalated quickly and get the devs involved, create an o365 trial account, make sure it has a null.onmicrosoft.com domain - that's commercial.
For commercial, you're connected to a tech, which is outsource through the typical firms, e.g. Teleperformance, Experis, Unisys, etc -- they don't care but they have an SLA to follow and if you give them negative feedback, the case will be escalated as the team lead will question why they got negative.
For example, a typical agent would have 100-120 cases a month. CSAT can not fall under 92%. Yes, 92%.
Escalations on a negative feedback ticket removes that ticket from that techs queue, so by rating it negative and not letting it be closed will get you the quickest service in terms of escalation because the agent and that agents Team Lead will escalate it to the NEXT team that has meetings with QA and the Dev's in India w/ Wipro and is the quickest way to get it resolved.
Or, just prove that there's a way it can be a security vulnerability and get a 10k check. I would but, I think I'm disqualified.