Unless we are talking about in-season attraction, I really don't worry about clover losing its appeal. If deer aren't eating my clover, it is because they found something better. I always mow my clover fields right before the season. I tolerate a lot of weeds in my perennial clover over the summer. I mow just before our cool temperatures and fall rain favor cool season clover over our summer weeds. The clover really takes off. I don't see why I'd treat an annual much differently. The only reason I can think to mow otherwise is to maximize reseeding if you are mowing it in bloom.
Thanks,
Jack