> bandits have higher statistical power, but also higher false-positive rate; false positives can be quite high cost since they cause thrash and require time to investigate if a feature that tested well does poorly in production

Not sure what you mean by this. Higher false-positive rate compared to what? And given that bandits do not run for a predefined amount of time but converge at a rate proportional to the evidence (as opposed to your typical AB-test), a higher rate at which point in time?

Perhaps you mean that, because bandits typically run longer, there's a higher chance that they'll select an alternative that offers only a marginal improvement on the status quo whereas short experiments would just say "nah, no evidence that one is better than the other" and thereby get rid of a lot of noise?