Ah just saw this, I replied over in acro forum.
I don't think you needed such a small dose BCS or a skip altogether, though no real harm done. BCS is usually half dose, so around 10U would probably have been ok.
How long has she been on cab now?
It's possible you're starting to see some results from that, so I'd take a larger than usual reduction. From 21U you'd usually reduce to 18-19U, but I'd go 17U to be on the safer side. Hold it for a few days to let the depot stabilize after the 5U tonight, can always take her back up if needed. But please wait for Wendy to reply in the other thread.
More detailed explanation - if the cab is starting to work, it means more insulin is going to be suddenly getting through to the cells in the body. So you must be very careful here, when in doubt take larger reductions, and earlier reductions than the dosing method calls for if she really seems to be on a mission. The combination of such a large depot plus more insulin getting into cells can be a bad combination. Please feel free to tag Wendy and I whenever you need advice.
See my spreadsheet from July - that was our ride down on cab. 13U to OTJ in 2 week span.
Edit - I just saw the cab dates on your spreadsheet. At this point I would assume you're seeing cab results and proceed very cautiously. It takes most cats about 6 weeks to start getting some movement, plus you changed to daily last month