Project Deliverables - Does the Customer Understands its Purpose?

90% of the ERP Projects, we put the Project sign off completion based on either Miles stone based Phase Completion like (Phase 1, Phase 2 or CRP 1 completion, CRP2 Completion, UAT Sign off) or Project Deliverables Sign off based completion (PM Deliverables like Project Plan, As-Is Documents, To-Be Documents, Functional Design, Technical Design, Test Scripts, User Guides etc.,) and Payments are linked to sign off.

We study the Customer background and if they are matured having few systems, Processes and Procedures in place, then we adopt Project Deliverables based sign off, so that they will have some basic understanding of the purpose and meaning of what is Project Deliverable and provide a sign off

On the other hand, if the Customer background is nascent and having more of manual Processes and Procedures, and type of Industries also like Construction Industry, then we adopt Milestone based completion sign off as it is difficult to make them understand the purpose of Project Deliverable and get sign off

In spite of all these, in my experience getting Project Deliverables sign off ended only in following three modes

1. 50% of Customers just go through the Functional Design, Test Scripts and User Guides and just ask one question, by signing this will it have any issue and then they will say blindly, "I trust you Siva and Sign it". Very few Customers, we make even a Presentation of each Project Deliverable and explain page by page, but they will just listen and not even debate on any Process or Point and then they blindly sign off. Hardly 5% will put whole heart effort to read, understand and correct those documents before sign off
2. 30% of Customers will say "Ok, You demonstrated and Provided me training and just taking sign off for that in a document form because your payment is linked to it, Correct" and Sign off
3. 20% of Customers, it is Herculean task to get sign off. They neither understand what is a Project Deliverable nor listen to what you explain, what they need to do and if you get a sign off from such Customers, it is really an achievement. Their concern is by signing the Project Deliverables, their Job is at stake and if Payment for the Project is released, then we will not be under their control. This is their perception and opinion

Another very critical issue is there will be a clause both IT Team and Business needs to sign off the Project Deliverable wherein One will Provide and other will not. This is another headache

Am I making sense?. What is your experience?