@weLees the Process for reviewing classic confinement snaps details the qualifications that need to be provided for classic confinement. However, there are still a number of unanswered questions from this thread - in particular you still have not explained why you feel the snap needs write access to all of /dev - if this was granted it would enable a snap to take ownership of the device it was installed on - as such this is a very sensitive permission, but you do not seem able to explain this request.
If you want your snap to be granted such expansive permissions you need to be able to explain this to the reviewers so that can adequately assess the request.
Please can you take a closer look at this thread and answer the various questions in as much detail as possible so we can try and help you? Otherwise I don’t see how we can help if you are not able / willing to provide the requested information. Thanks.