Need Matrix Manager feedback button to get disabled or greyed out

Summary

Requirement to make Matrix Manager feedback button to get disabled or greyed out

Content

Hi All,

          We have this requirement to enable matrix manager feedback in our performance documents. I enabled the matrix manager and he is able to complete the employee evaluation also. Now we have this requirement where we want matrix manager feedback button should get greyed out after matrix manager completes the evaluation. Is there any possibility to grey out the participant feedback button once feedback is provided.

Following things are in place

1. Employee self-evaluation

2. Manage participant feedback. (Begin button on this stage should get greyed out or should become "VIEW" after matrix manager completes evaluation) Matrix manager gets direct access to the document without line manager trying to get to add him as a participant. This configuration is also working smoothly.