Hello Jennifer,
We've got the two types of attributes in drawings balloons: String and Integer. depending of the complexity of the product and number of items in the drawing.
In general String for simple products with just symetrical or topo info (right or left , etc ...)
and integer for more complex assemblies with lot of components .
How do you think "un restrict" ? by removing the integer constraint for the Line Number ? Cause in most cases , it is mandatory for ERP BOMs ...
In our case, your 2 prefs and the actual constraints are OK.
May be consider to be able to synchronise any IBA and not only line number or find number ?
please note an example in another Creo idea of one of our CAD administrator
http://communities.ptc.com/ideas/2603
regards
Gregory