Considering the scope and extent of the geometry, as you've mentioned the "pattern" feature would be difficult to implement,
But, you can rely on the "Object Generator" feature if you want to define a connection or a boundary condition, etc. and directly replace the object with a boundary condition. It is quite a robust feature helping in the automation of several tasks, thus increasing productivity and efficiency.
Please check the following links for more information on the object generator feature-
Generating Multiple Objects from a Template Object (ansys.com)
Automatically Generate Objects Scoped to Contact Regions (ansys.com)
Object Generator in Ansys Mechanical - YouTube
If you're looking for a solution from a designing point, Ansys Discovery has a great feature to automate tasks, it involves a bit of coding using IronPython, but that too can be avoided to an extent if you use the "Record" feature and perform the operations.
Please check the following course which explains in detail the processes and the features which Discovery offers for automation or via scripting -
Scripting in Ansys Discovery | Ansys Innovation Courses
Hope this helps!
For more exciting courses and certifications, hit this link: Ansys Innovation Courses | Ansys Innovation Space
If you are not able to open the links, refer to this forum discussion: How to access the ANSYS Online Help