I made a post earlier that received pushback for being unhelpful, so I am reframing as a question.
It has been asked and answered many times that you cannot use Google Wallet for NFC payments on grapheneOS. What I don't see clarified is this - can Google Wallet be used for NFC purposes that are not a payment? For example, could Google Wallet be used to store a university ID while running on grapheneOS?
I tried to do this myself and was not able to add my university ID to Google Wallet. Here is what I did.
On a Pixel 9a I installed grapheneOS version 202611300. Using Google Play Store, I successfully installed Google Wallet. I successfully added a rewards card for a local grocery store to the wallet.
I then followed my University's instructions to add a mobile ID to Google Wallet. (I have done this successfully before on my previous pixel running the stock Google operating system). This is done through an app called eAccounts, made by a company called Transact. When I follow the instructions, after authenticating myself with 2FA and agreeing to the Terms and Conditions, I am brought to an error page saying "Google Pay can't be used on this phone. Your phone may be rooted or altered in a way that doesn't allow Google Pay to confirm that it meets security standards". I tried restarting the device and giving Google Play Services, Google Wallet, and eAccounts every permission possible before trying again, but the error was unchanged.
My university only gives options for Google Wallet, Samsung Wallet, or Apple Wallet to use a mobile ID. If no one is aware of a workaround for me, then it seems to me that Google Wallet's ban for NFC on grapheneOS is not limited to payments, but also extends at least to some University IDs. Universities often allow on-campus payments to be made through your ID/account, so perhaps that's why I can't even use mine just to tap in to identify myself.