I have yet to see a definition of "default URL". I assume that it means whatever URL is hidden inside of the RokuAds component and that by supplying no URL manually, you opt into using the unknown default. I would simply like to get my pre-roll ads going again since my channel is almost a clone of the older Direct Publisher version that Roku quickly started showing real ads on.
And if today magically Geico starts showing ads like they did on my DP channel, that I am actually getting revenue from this instead of finding out 4 months from now I didn't put in the right AdUrl to get paid. This is ridiculous.