This is my Seiko 7A48-7000. I think it can just about qualify for this forum as it's a direct descendant of the 7A28, which I believe was the first quartz chronograph, and it can be easily regulated. I was lucky to pick up this completely unmarked example which must be about 25 years old. It's not my choice for a daily wear, as I want to keep it near perfect, and the crystal is mineral glass, not sapphire. Plus, it's not very readable - the hands are a bit thin and the date needs a magniying glass. BTW, apologies for having photographed it at exactly New Moon, so that this complication is invisible.
The regulation is in 0.26 sec/day (95 SPY) steps, so it will always be somewhere in the range of +48 SPY to -48 SPY. The smallest variation I can get is -34 SPY - not too bad, but a bit of cheating can improve on this.
Unsurprisingly, the watch doesn't have an independent hour hand, so it has to be reset twice a year at DST changes (I'll assume 6-month intervals to keep it simple). So the maximum variation between resetting is only 17 sec.
Then, by initially setting the watch to 9 seconds fast it will be about 9 seconds slow by the next DST change.
Voilà! My watch runs at +/- 9 SPY.