Different tools that could be useful

• Last Mile: Drawing tools, DGN Exporter, ...
  https://communities.bentley.com/products/road___site_design/w/road_and_site_design__wiki/52965/last-mile-utilities---set-of-utilities-for-openroads-and-openrail-designer
• Migration Utilities: XIN, Excel tools, ...
  https://communities.bentley.com/products/road___site_design/w/road_and_site_design__wiki/41342/migration-utilities

And some more here: 

VBAs and DLLs for Custom Functions

Featurized Blogs for good references:

https://communities.bentley.com/other/old_site_member_blogs/peer_blogs/b/marc_thomass_blog