Increase External ID field Character limit to minimum of 40.

Yes. Make it happen, because unfortunately Concur ID (SAP Expense System) can vary form 35 to 50 Characters and this would be an obvious value for the External ID, so that you can do item-to-item lookups. I have no idea why they have such beastly ID lengths, while Salesforce has it down to 15 Characters, but this would definitely help and avoid a "costly" Custom Field that then requires an additional lookup.

Thanks. :)