Different methods of blocking data subscription besides Gy OCS

Any guidance or suggestions on different methods of blocking data subscription besides Gy OCS?

I know we can block data with ODB on the ISD, but what about the ims apn (we use s8hr) or to exclude an apn like mms?

Another option is to just return a list of apn that does not include the typical data apn, but how do different handsets behave?

Goal is to reduce signaling on the s8/gp interface but more importantly to have good experience for the user who is blocked (ie don’t have constantly searching for new network) and save battery life on the handset. Any thoughts?

Thinking might be a neat trick to return unknown subscriber or something like eps service not allowed to the location update?