Had a problem with invoicing - when I sent out the invoice to some new clients they reverted to GST inclusive, which I didn't pick up on for weeks - as it had always previously been GST exclusive.
It would be great to have a button in settings that we could lock so that it automatically came up with the company setting (unless we wanted to change it) - so you would have to go to settings if you wanted to change it, not be in invoicing.