Should building support not include help with blender designs/ issues? There are blender support forums fully dedicated to that topic that could be more helpful for that user possibly.
Modeling, inside or outside the blender, can be considered a form of construction.
And if the subject includes the blender, but it’s connected to roblox studio, then yes you can use this forum to ask for help.
Modelling falls under that category. Building support is for anything related to creating geometry for Roblox. Doesn’t really matter whether it’s Studio or Blender. It might be more intimidating to post on the blender forum than it is to post here.