It's a gradual process - you want to shoot lower and lower numbers until you're shooting everything over 90 (since you're following SLGS.) Shooting lower will help you lower his entire range of blood sugar and help it flatten out. However, each time you shoot a number lower than you've shot before, do it when you can monitor afterwards. If you're going to be off to work and he's starting lower than usual, either figure out how to come home and test him, figure out how to get food to him on your schedule, or be conservative in your dosing.
Here is a post I wrote someone else about this - there are links to spreadsheets and other information that is worth reading.
There isn't any way any of us can give a specific number that is safe to shoot and go to work. We've had cats here that can go from 400 to 40 in a couple of hours (Sienne's Gabby and Dyana's JD are 2 examples). You take what you've learned about Nacho and make the best decision you can. Punkin never dove fast, so I didn't worry about that particular scenario. I had a timed feeder - and Punkin was trained to eat from it when it opened. So if his preshot was lower than typical, I loaded up the timed feeder and had it go off several times. Someone later told me that they had 2 timed feeders, so they could schedule 8 openings of the feeder. I thought that was brilliant. There are lots of tips like that in the sticky at the top of this group about how to follow Tight Regulation while working full-time.
It's possible - just takes some thought.