We shoot all our commercials in progressive. Just started using a digital distribution service that wants interlaced files. They say that if we send a progressive file they are going to convert it their end into an interlaced file. They said that there might be potential problems with animations if they are part of any part of this and future adds. Anyone had any problems or experience of this first hand?
The information you have been given is correct. And, while posting everything as Progressive is not wrong, you do need to bear in mind that the television broadcasting process is interlaced.
Interlaced vision is far less forgiving of fine details.
Ideally, you should be watching your product in an interlaced environment even though you finish in progressive.
I'm in a similar boat; we finish all our television as progressive, but I watch it via a Blackmagic card on an interlaced monitor. Sometimes we have to blur or unsharp some vision to get rid of flicker or moire patterns that appear on the interlaced screen that don't show up in a progressive environment. (Not even on the same monitor, which is proper broadcast monitor and can be set to Progressive.)