A+ Content Backend Keywords Confusion

I paid someone to create A+ Content last year. But I’m trying to improve it.

But I’m slightly confused with the backend words. As I understand, you should never REPEAT keywords as high value keywords are already in Title, Bullet Points and Description.

However, according to Amazon’s guide in A+ Content creation , it suggests something quite different.

Summary: Should backend keywords be repeated ?

Am I required to submit image keywords when I upload an image?

Yes, you are required to submit image keywords, also known as alt-text, when uploading images. Image keywords should consist of a simple sentence describing the image (for example, Blender on kitchen counter next to fruit, yogurt, orange juice, and a smoothie glass). Image keywords do not appear on the product detail page, but are available on screen reader applications used by customers with visual impairments to learn more about your products. They also help your product appear in search.