I am growing Triple Crown and Chester blackberries for the first time. The will get some shade from asparagus. I have heard that they need full sun, but I have also heard that sometimes intense heat (zone 8) can stress the plants, and that some filtered shade improves vigor and yield. I hope that, by next year, my blackberry plants will be tall enough to get above the asparagus for a bit of full sun, but with some shading on the lower parts. Am I setting myself up for failure?

The two berry varieties you mention are among the most vigorous and there is no way that asparagus will out-compete them for sun. Triple crown will have better quality fruit with morning sun only, otherwise the berries are vulnerable to UV damage. If possible, from south to north, plant asparagus, chester, then triple crown.

South is a row of asparagus, with triple crown and chester in the same row behind. They, in turn, will be shading blueberries, which eventually will be the same height as the blackberries. I can prune both with that in mind. There is a garage a bit behind, so they will get late afternoon shade. I think you are spot on about Triple Crown being more sensitive to heat intensity. I read that somewhere, but I don't know from experience. Thanks for sharing your thoughts.

you' don't need to space corn 15 in between rows.

How much would you space?

the same as distance between plants . that depends on type

corn.