Not sure of the actual stats, but consider a risk assessment.
How often is your engine likely to fail at 500 feet on final?
Statistically, not often. That's not to say it won't ever happen, however the probability is not high in a (relatively) modern single. You have to balance this against the possibility of screwing up a landing having done an approach which is potentially too steep. You're increasing the probability of this by doing something other than the standard 3 or 4 degree powered approach, although once again, the probability itself is not that high.
At the end of the day, it's a balance of probabilities and you have to decide for yourself. From my own point of view, I'd work on the probability that the engine is likely to keep going. If there is a likelihood of it stopping (perhaps following rough running for example), which is likely to make itself apparent long before your approach, modify your plan accordingly.