Thank you for the reply. Let me ask you, why premium is fixed at 10%? As I see it, this would make sense only for large quantities of small payments. I.e. it seems like you're expecting exactly what you say you're hoping to eliminate: small feature requests, bugfixes, maybe some integration tasks, docs, etc. How about yearly support contracts?
One of us misunderstood what they do. The way I read it was that they establish a contract between dev and corp with regular payments (of which they take 10%), in exchange for this the corp gets the things listed above like prioritized bug reports and so on. But they don't pay for the single bug fixes or anything.