Had to come back to this... man, not going to lie: Reading those "options" actually made me angry and I couldn't let it go.
There's so many places taking complete advantage of people in the EV space it seems and it's super irritating to me. It's especially bad when I end up cleaning up after them, too. I've serviced at least a dozen cars now that have had completely botched service done at places claiming to be able to do cheap repairs on battery packs. I won't generally name such places, but if they're saying they can replace a module, cut out a cell, or some other butcher job on a pack as a "repair", then they're probably in that group.
I'm fully aware that not everyone is able to get all of the information they need to understand this, and I never blame or shame victims of scammers for being taken advantage of. But it's especially annoying when someone I've pretty directly given advice to pointing out that such "repairs" a) do not work, and b) show that the people offering them are unqualified to work on these things.... and they do it anyway.... and then X months later come back because they still need real service.
I've actually had someone pretty much cuss me out the other day over this. I explicitly told them the alternative non-option they were looking into was guaranteed to damage their car and that I would not be able to help them for a reasonable price later on if they went that route. I didn't hear anything for something like 7 months. Then they call in, pretending like no one at 057 had spoken with them, gives their VIN, our notes come up clearly suggesting they went with a pack-butcher "repair" sometime last summer. We explain that such a core pack isn't acceptable for any of our replacement or upgrade services, they initially lie and say they never did anything of the sort and have been waiting to get it fixed (despite saying moment earlier that it just happened). I eventually personally get on the phone, explain the situation, clearly recognize and recall them from previously, and they eventually admit that they went another route and paid some other company $6000 to basically just break their pack. That company won't do jack for them now, and now he wants me to honor an estimate range given 7 months ago before their core pack was made useless... Sorry, that's not how it works.
Oh, and I find out later in the conversation that Tesla won't accept their core either, due to "modifications", and wanted a $20,000 core charge on top of the normal replacement costs. Ouch.
Anyway, I wish there was something I could do to get through to every single Tesla owner that there is no cheap repair for these issues in 99% of these cases. The BMS is very good at its job, and if it says there's an issue then there's probably an issue. Resetting things helps nothing, and there's no software fix for any of these problems despite claims to the contrary.
Your options are: replace the pack.
That's pretty much it. (I've got one other potential option in the works that might work out in maybe 30% of cases to save someone a few bucks getting their car back on the road, but it's still expensive, not the best option for most, and not something anyone else is pulling off, frankly.)
Option 2 was never a fix, and has been proven over and over that it can't be done. It at best kicks the problem down the road a few months. I guess that's great if you're a con-artist and want the car to seem usable to flip it or something and screw the next owner, but not great if you actually want something fixed. (Yes, I've had a few customers who have had this happen to them, sadly. Free of charge I pulled logs for them showing what was done to the car, and at least one of them is suing the seller of the car now. So don't do this. I'll help the victims of such fraud go after you and I'll do it for free.)
And good Lord, $5850 for "software rebalancing" ... that's got to be the worst scam in this space I've heard to-date. And I've seen a lot of people get screwed over the years by companies claiming all sorts of nonsense. But damn, that just boils my blood.
Seriously, just run away from those "options". I'm not even trying to push my own stuff here, because I don't think it's the best option in your particular case. Just go to Tesla, get the refurb pack, and move on. Either that, or put the car up for auction and cut your losses. Just please don't let some company talk you into giving them money for a non-fix, and probably shouldn't give any money to companies that suggest a non-fix at all.