So, is the responsibility of the engineer to actually deny the client the opportunity to alter?
Is the responsibility to interpret as denial the provenance of those who have a stake in the position of denial as perjorative? Is the sentence as convoluted and as opaque as I can make it? Is the rhetorical question all about rationalizing a lazy work technique? Can I stop with the questions?

Dylan wrote: What you're asking for is a way to freeze the exact mixes in time, yet still change them at any point in the future. I can't think of a single technology that will allow that.