I'm asked to send a 360 Feedback over Slack

Okay so I work in one of those amazing tech companies where you have to submit 360 feedbacks every 6 months & will be PIPed etc. As here because unfortunately the programming related communities seem pretty inactive.

My former manager had putted me on a PIP before switching teams (first time ever in my 10 YOE). I somehow managed to survive that and now was asked to provide a 360 feedback for this old manager who PIPed me.

I didn’t bother to answer the request, but now the skip level of that manager reached out via Slack and wants my feedback because they’re having „additional calibration sessions“. He asked me to provide it via Slack „to save time“.

I asked ChatGPT to word it in corporate speak so it sounds diplomatic even though it’s like 70% „constructive feedback“, but I’m wondering if I have anything to gain from this.

Would you send the feedback? Is it weird that they want it via Slack when it takes like 2 minutes more to fill this out in Workday?