In general this is my experience as well. Out of thousands of purchases for code plugins for Unity, I’ve only ever given 2 refunds (only 3 requested). One of the refunds was a person that mistakenly thought my product worked with the Apple TV 3 instead of Apple TV 4, and the other didn’t read the description of controllers supported but it was a pretty long list so I could see how that could happen so I granted the refund. I will say though that the 3rd though claimed he accidentally had it in his cart but when I checked the invoice it said he had downloaded it (totally different than just purchasing) so that was obviously not the truth. Then I looked up his info and he was one of the known pirates so obviously I didn’t bother corresponding with him. That being said I don’t think the pirating hurts sales at all, I just didn’t want him to have his cake and eat it too since it was obvious what he was doing. If I wasn’t 100% sure I would have granted him the refund because it’s just good business practice. I can’t speak for the Unreal marketplace but if the refund request rate is normal it’s really how you should react as a business giving refunds. However, not sure of the accuracy of some of the publisher reports but if the refund rate on the marketplace is markedly higher then it makes sense to tighten up the return policy because obviously system abuse is going on and word has gotten around and more than normal is doing it.
As far as a policy is written though, it really should be a sales are final after download policy except where required by law (by far the most common EULA language for digital assets), unless there is something wrong with the description or other wrongdoings by the publisher. EU and other countries law obviously takes precedence but at least in my sales data for the past few years, those countries only account for about 25% of all sales. The US is the highest percent of all countries at 51%. Obviously the marketplace is different but I would expect it to be similar. That way each publisher can run their business the way that they would like and can combat systemic abuse if it ever occurs. At least on the Unity Store every once in awhile it does occur though in one form or another, either someone buying a lot and just asking everyone for a refund, or perhaps threatening with negative reviews if no refund is granted. The biggest thing is being able to identify when abuse is occuring and then banning the user, as long as this occurs the refund rate will stay low.