Like many, we had wanted a way to update our MIB database file automatically and negate the need to do so manually. The attached script is one that I wrote that we set up as a scheduled task on the server where Orion is installed. You can run it as often as you want, we do so weekly, but there is a caveat. It seems that the new file will only go into effect upon the next time the Orion services are restarted. In our case we have a weekly restart, but be aware that this caveat exists. You may choose to run the script an hour or two before your patch deployment windows, or before some other time your servers / Orion services restart.
We've been using this script for months with no ill effect. While the script does overwrite the "production" copy of the MIB database file with the updated one this does not cause any issues, but again it does not appear that any new MIBs contained within the file go into effect until at least the services are restarted.