You’re absolutely right regarding Unity. And yeah, going back to pilfer your clients piggy banks is horrible optics.

The only times I can think of when a company is justified in retroactively requisitioning cash from a client/business partner is when that client/business partner is either A) They (client/business partner) failed to honor their end of the agreement B) They lit your building on fire (i.e. damages)

Barring those two, not really anything else I can think of that warrants a company saying “oh you also owe us more money now based on your past sales.”

When I was thinking of short notice, however, I was thinking Reddit.