All the nonsense about going clipless and the ensuing inevitable falling is exactly that, nonsense.

It's way overblown and too many people put way too much emphasis on it.

I'd certainly wait until after your race because it simply doesn't make sense to change up things too much for familiarity reasons.

When you go clipless just practice a little bit, keep things easy in terms of release and you won't have a problem.

the most important thing is fit, and cleat placement is critical in terms of being good to your knees. Try not to guess there.

For your race, go with what you know, and move yourself to clipless when you have the time to get used to it.