Hi pipefitter, good to hear that you gave yourself a break from ruminating for a bit

Am I reading you correctly, that you're kind of conflicted about getting back together with her?
I was ready to proceed with life minus my pwBPD.
There's no right or wrong answer, just putting the pieces together, as I'm seeing you feeling ready to move on without her, and also posting on the "Bettering a relationship" board. We do have a
"conflicted" board too, if that's helpful!
...
So, approaching your question about her text from a "how can we make this better, or at least, not worse" perspective:
The first thought that came to my mind is that it's as much or as little of a "temp check"
as you make it.What I mean by that is -- there's a sense in which whatever she means by it, whatever she wants, ultimately, you have 100% control over what you want and how you respond. It may seem like a confusing text as long as you don't personally have clarity about what you want in your life. If you aren't sure about getting back together or not, then the text may seem more confusing ("is it or isn't it"). If you have clarity about what direction you want to go, then it becomes a moot point what she "means" by the text.
So, one idea is to start there -- dig into yourself and find that vision for what you want. It could be: you learning and working the tools and skills here, and getting back together with a new, healthier approach. It could be: you making a personal choice that the door is closed on the relationship, and working through the detachment process. Or it could be something else. My thought is that until you have a clear vision of what you want, her texts will remain ambiguous to you, and you might hang a lot of weight on them, hoping that she, a pwBPD, can provide a path forward.
Whatever direction you choose, it might be important to know that you'll likely have to be the "emotional leader" in the process. She struggles with a profound MH disorder, and so looking to her words and texts for guidance or clarity won't "get you out of the woods", so to speak.
...
Another way of looking at the texts is this:
Some pwBPD (even if they believe themselves to be emotionally advanced and amazing communicators) use unclear, unstraightforward, and passive (and/or passive-aggressive) communication. The words, when typically understood, mean one thing, but there can be an emotional undercurrent of "meet my needs" that's unspoken.
A dysfunctional thing that can happen in relationships with pwBPD is that the "non" gets to a point of acting like "well, even though she said 'just go to the store and get milk', I know the true meaning, which is that she wants me to stay home with her, so even though her words said Go, I'm actually going to stay to make her feel better".
Treating a partner like they don't mean what they say, AND treating ourselves like "it's our job to truly interpret their words", is unhealthy.
And, a couple of things can be true at once. It can be true that we can understand that a pwBPD might have a different meaning behind the written or spoken words... AND, at the same time, we can "treat them like they mean what they say", and not play the game of "chasing the emotional meaning". It is enabling and doesn't help the pwBPD grow (or grow up!) when we deprive them of the opportunity to communicate clearly.
All that to say -- whatever she "means" by the text, it's a mature, healthy move to take it at face value. Don't do her work for her of assuming "but I know what she really means". Leave that opportunity open for her. And in the discomfort of waiting and wondering, turn that energy inwards, so you can gain your own clarity and vision about what you want, whatever she says or does or doesn't do or doesn't say. You have that control over how your life moves forward.
...
Lots of food for thought...
kells76