61 char limit on PostbackUrl for post-in orders

There is a 61 character limit on PostbackUrl for post-in orders. This seems like an unusually low limit. Could it be increased?

To reproduce post-in an order with
<PostbackUrl>https://subdomain.maindomain/incoming/shiprush_results/1234567890ABC</PostbackUrl>

View the order and exported the ZPK file. The xml now has
<PostbackUrl>https://subdomain.maindomain/incoming/shiprush_results/12345</PostbackUrl>

Thanks,