I love the new flowers added by the mod but I noticed something that makes them different than other plants, I suggest you randomize the position of the flowers on the block they're placed on to make it look more natural like vanilla plants

Here's the vanilla wither rose in comparison to the modded roses

After some investigation, this issue was caused by a bug in Blueprints FLOWER property in PropertyUtil. I have submitted a bug report to them, meanwhile I've made my own flower property that fixes this issue.