I have no clue about personal information consent form. But for additional documents, you can share any documents that you want to submit which you could not provide in the main application. In my case, I worked with more than 3 employers in the last 10 years. So, I expanded the missing details in a letter adding remaining employers that I couldn't submit in the main form. Think of it as a custom document that you can provide with relevant documents if they are not captured as part of the existing forms.