Thanks
I patched the script on 3.1 doing this on the db:
update metadataserver_script set "default"=FALSE where name='30-maas-01-bmc-config';
Then:
wget "https://git.launchpad.net/maas/plain/src/metadataserver/builtin_scripts/commissioning_scripts/bmc_config.py?id=b0956f649955f27657bcc635c04cb3e7809c4060" -O bmc_config.py
maas REGION node-script update 30-maas-01-bmc-config script@=bmc_config.py
And setting back to default:
update metadataserver_script set "default"=TRUE where name='30-maas-01-bmc-config';