Self Registration auto generate USERID as per criteria/recipe

As it can be complicated to reject/delete users that have self-registered, due to their information remaining in the MongoDB, and deleting them under the users section and the person section doesn't allow them to simply re-register using the right credential format, as they'll get an error saying "USERID already in use", I suggest that there would be a way to have them auto generate the USERID based on criteria's/recipe/requirements (defined as per client). 

An example of coding to be used to achieve this would be: 

(lastname+2first letters of first name)

Similarly to how one could apply this automation script, I just don't know if it can be done in Manage or would it be done by IBM's SRE team as it's at the MAS level environment?

from psdi.server import MXServer

# Get values

first = mbo.getString("FIRSTNAME")

last = mbo.getString("LASTNAME")

# Basic validation

if not first or not last:

return

# Build base username: lastname + first 2 letters of firstname

base = (last + first[:2]).lower()

# Clean spaces or unwanted characters (optional improvement)

base = base.replace(" ", "")

mxServer = MXServer.getMXServer()

userSet = mxServer.getMboSet("MAXUSER", mbo.getUserInfo())

username = base

counter = 1

while True:

userSet.setWhere("userid='%s'" % username)

userSet.reset()

if userSet.isEmpty():

break

else:

username = base + str(counter)

counter += 1

# Set the generated USERID

mbo.setValue("USERID", username)