I am only trying to understand and I may be wrong, but doesn't "strict isolation" have to do with routing only? Reference to a node object in /Common from another partition perhaps should just be OK?
Not sure which version of BIG-IP is being used here, but I have run into an issue on 11.3 with just such a reference, not with the device on which it was configured, but the conf wouldn't sync to the standby sucessfully.
I remove the noded from /Common and re-built them in the same partition the application ran from and things became fine.
I opened a case with Support and was advised to re-build the DB, but I would like to wait until some of the other issues I have are resolved first.