It would be great to improve shell feature.
PTC explains that there is a limitation with shell feature when exterior corners (round transition) are defined with more than 3 edges and thickness passes the corner from 4 edges to zero edge.
https://www.ptc.com/en/support/article/CS323249
It is OK if the corner is defined by 3 edges. Creo can offset the exterior corner from 3 edges to zero.
I compared SolidWork 2019 and Creo7 shell features.
Have a look at the video and see that SolidWorks allows shell feature where Creo fails.
Best regards
Nicolas
