Well, in the end after closing (which involved draining and refilling), I spent 4-5 days getting the chemicals balanced the way I wanted for winter before the water froze. A real PITA since my pumps were winterized and I ended up having to use an extra drop in pump to circulate water for those days but...
Right before starting to adjust the chemicals:
pH: 7.9
TA: 330
CH: 125
After a couple days of adjustments:
pH 7.5 (new plaster, so anticipating a slight rise over winter and before opening)
TA: 110
CH: 335
So I'm happier overall, and my CSI is about where I want it (even though it's about the same CSI, give or take, it's just achieved differently). For all I know, having spent the time to do the chemical changes won't make one bit of difference over the next 4-5 months anyways with the newer plaster, but... maybe it'll help and I -feel- better having done it.
Next year my pool service company agreed to do the closing without draining and just air lock everything now that they've gone through the closing process with me and understand my entire system better. Closing a real PITA with 7 different individual bodies of water that need to be drained, 6 pumps, 2 filters, 37 in floor heads/Caretake system, an upper spa/waterslide, waterfalls, beach jets, disappearing edge, and countless other things. Each year, closing has taken 2 guys (with a bit of help from me) an entire day to get everything done, and I feel like my guys this year we really efficient and did a good job, it's just a real headache closing this pool.