Interaction of Contract Deliverables with Procurement and Contracts

Currently, when creating a deliverable within a contract, it is not possible to include flexfields of any format other than 'Character'.
This directly impacts processes where an external deliverable (filled out by suppliers) with an expiration date, for example, is not supported by the function. The deliverable does have expiration settings, but they only support cases where the internal contact has knowledge of the information.

Furthermore, the deliverables do not interact directly with the contract, in the sense of creating 'blocks' or changing the contract status, for example.
We currently have the following scenario at a client:
A contract deliverable is created for the supplier to fill out the necessary data (including the expiration date of a certificate). When this certificate expires, the contract's status should be changed to 'Hold'. However, this does not happen automatically, and even if the user makes this change manually, the purchasing documents related to the contract remain in 'Open' status (e.g., agreements and purchase orders). Furthermore, even if a contract is in 'Hold' status and has a purchasing agreement as 'Open,' it is still possible to create Purchase Orders linked to that agreement, which makes no sense since the contract is