1. The coordinator can link input-outputs even with the hardcoded key
The client doesn't verify that the unblinded signature is actually a valid RSA signature for the hardcoded public key. The coordinator can still do tagging and link inputs-outputs after output registration.
2.
newNew DoS vector is introduced in the code
If you confirm an input getting a blind sig, and then just time out, you can later use the same unblinded sig in a subsequent session and register an additional output which is a DoS issue.
Related tweets by nothingmuch:
https://xcancel.com/not_nothingmuch/status/1937176085461930033