There is no such thing as progressive PAL. You can have a progressive image stored in a PAL signal. But a PAL signal (so the signal going to a PAL monitor) will always be 620/50i.
Inside, the Avid will treat the images as being progressive. It’s the output boxes that need to interlace.
In HD, it’s different, as HD has 23.976p, 24.00p and 25.00p modes, that most HD-capable monitors understand. Even then, if you use HD-SDI connections, it will be PsF.