Use SCI_SETCOPYSEPARATOR for better multi select copy. Doesn't improve multi select paste unfortunately.

Projects/Src/IDE.IDEScintEdit.pas

@@ -227,6 +227,7 @@ begin
   Call(SCI_SETMULTIPLESELECTION, 1, 0);
   Call(SCI_SETADDITIONALSELECTIONTYPING, 1, 0);
   Call(SCI_SETMULTIPASTE, SC_MULTIPASTE_EACH, 0);
+  Call(SCI_SETCOPYSEPARATOR, 0, LineEndingString);
 
   AssignCmdKey('Z', [ssShift, ssCtrl], SCI_REDO);