Block or just quietly disappear?

I recently went through what I feel like was a ‘soft’ discard by my best friend who I suspect has BPD. I experienced my first ‘split’ from them a couple months ago and posted about it here:

https://www.reddit.com/r/Codependency/s/JLuDZTza7M

They felt remorse after the conflict, we worked through it, and I held them accountable and they seemed receptive to what I was saying.

Recently, they flew off the handle at their roommate who tried to hold them accountable for paying bills late, and the rage they were showing me lowkey spooked me, and triggered the same fear I felt when they went off on me. I placated them nevertheless, and did my best to hide my discomfort. We grabbed dinner and had a good night together.

A few days later she asks to talk, and tells me that she will be “stepping back” from our friendship because it was unfair for her to absorb the blame for the abusive outburst I held her accountable for two months ago, and that I don’t allow her to exist in her full emotional complexity (aka vindictive and destructive) because I’m always bogged down with “fear”. She said she is happy to revisit the friendship when she is done with her PhD qualifying exams, so it was open ended — but for me the friendship is over.

My theory is that she felt shame after how she acted with her roommate and felt exposed around me, therefore she needed to cover up her shame by making some shit up about why she needs to distance herself from me.

Anyways, I do not want her in my life anymore - but nearly all of our social circles are intertwined. She is more of a quiet borderline (I think) - I worry that if I block her she will escalate shit with me and involve other people.

From a purely tactical perspective, which will cause the least friction? I know I might be trying to control something I don’t have control over, but I guess it would help to know how others navigated this.