Hello Eric,
Have you tried the Dataform module? We are using Moodle 3.3.1 (Build: 20170710) with Dataform version 3.0.4 (Build: 2015111604) and Group Peer Review (see attachment). I love this activity. Itamar Tzadok presented Group Peer Review HERE. His second post there explains why you need the field type - dataformview - which has not yet been released with the latest Dataform version 3.3.2 but I am confident that it will be released soon.
Before you start developing a new plugin, I would give Dataform a chance and see if you can customize it to your needs.
With kind regards,
Hartmut