Daniel, please don't cross-post!
The Roof Surfacer addon is quite old and sadly hasn't been updated for anything more than pure compatibility, that is no improvements in the AC11 version, I think.
I don't know about the 2D issue you mention, I haven't tested the tile surface in AC11. Report it as a bug to your reseller, they will forward it to Graphisoft.
The inability to control the starting point is an old complaint. While not a bug, rather a lack of necessary options, I think you should report it too. The more complaints, the greater the chance that it will get fixed some day. Don't hold your breath though.
AC4.1-AC26SWE; MacOS13.5.1; MP5,1+MBP16,1