Nick, I have some of the same frustrations, although (fortunately) I don't travel often for work.
The pain is probably NOT being initiated by your employer, but by the IRS. Any time they convey money to you (whether it is salary or expense reimbursement or whatever) they have a burden to show whether it is taxable income or not. Without the documentation, both your employer AND YOU run the risk of the reimbursement transaction becoming subject to federal tax.
Obviously, SOME of their change in behaviour could be because they want to "save money" but let's not completely discount the chilling effect that lawyers and accountants can have on Common Sense.
I want a donut.
