My first thought is that when interacting with pwBPD in a case like this, it can sometimes go better to move forward "as if" their dysregulation isn't happening.
Unpacking that a bit with an example:
Last year we were set to take an international trip with the kids. We'd let the kids' mom (uBPD) know about it a year in advance. She was there 6 months in advance to help get passports. She has our phone #'s, email addresses, and we all know where everyone lives. All that to say -- nothing about this plan was a surprise and there were multiple well used familiar ways to communicate.
A few weeks before the trip, the kids told us: "Mom doesn't think it's a good idea". We heard this from the kids, not through an email/text/call/statement from their mom to us.
DH was getting pretty wound up and wanted to engage with that (i.e., JADE, convince her to change her mind, etc etc). We ended up moving forward with our plans "as if" we hadn't heard that stuff from the kids. She is an adult -- if she thinks it isn't safe for the kids, she has multiple ways to tell us, and plenty of time to do so.
Engaging with the implied communication (notice that yours is the same -- nothing is explicit, there are a lot of "maybe it means this, maybe it means that" questions, it's pretty nebulous what "not replying" may or may not meant) gives it a weight and reality it oughtn't have. It also means that instead of you being the stable emotional leader in the relationship, you are "hitching your cart" to the pwBPD's "out of control horse". Their out of control emotions are what's guiding the interaction if we engage with these nebulous statements or silences.
Instead, consider moving forward with stability and commitment to the plan (your option 1).
Giving the pwBPD an open-ended choice rarely ends well (2). You will again be left hanging, with them "leading" the relationship with their instability.
Pointing out dysfunction doesn't typically end well, either (3). If "all it took" to "make" a pwBPD function normally was shining a light on their behavior, then none of us would be here, and the BPD conundrum would be solved
Instead, that may lead to defensiveness, a "wall" being built, and them "doubling down" on it not being their fault -- not productive for moving forward.
Same with (4). Move forward with actions based on your values and wants, instead of giving that choice away and "hanging" on the possible answer.
(5) -- depends on what you truly want. I hear you saying you want to reverse the breakup and re-start the relationship. You can think about the options on your list and decide which ones are coherent with your values and desires. It's important just in general in life to have coherence and integrity between what we say we want and what we do. When there's disconnect, we get red flags in our life (resentment, feeling out of control, frustration, many other signs to ourselves).
(6) again, depends on what you want, who you want to be, and what course of action you can commit to.
Overall, it's good that you can hold back from emotional reacting, and give yourself time to list out some options for how you want to move forward. Responding from thought versus reacting from emotion is a wise way to go. Moreover, choosing to act based on your own values, in coherence with what you tell yourself you want, "takes back the power" in your relationship, instead of "giving it away" to someone who experiences unstable emotional extremes.
Keep thinking about what it would be like to "be the calm, stable horse pulling the cart" instead of "hitching your cart to the unpredictable horse". Model the managed emotions, flexible thinking, and reasonable responses that can stabilize interactions with pwBPD.
Interested to hear how it goes...