I did find a rule for graphic page numbering. Section 5.12.1 in Tactile Guidelines states that page numbers be assigned to all braille pages. It is not expected for the page number to be on the graphic.
If you are using the current version of the Swift Add-in with WORD there are tools to help with blank pagination for tactile graphics. It is very useful and eliminates all the code entry you need to do manually. If you are not using the current Swift and WORD you can go into DBT Help Quick Code Reference and choose all of the appropriate codes to input into you DXP file. I agree that it is cumbersome to do this in DBT but the Swift tool does help some.
Thank you for your look up in the tactile graphics guidelines. I have used all page numbers on all pages in the majority of my work. A lot that decision may be the preference of the agency/customer.