Ability to separately change the caching period for each Live model

At the moment, the caching period of live models is set for the whole instance which removed flexibility where you'd want the caching period to be different for exceptionally large models.  For example, we have a table we have to ingest via a live connection as it is too big for elasticubes - but wouldn't want the caching period for this live connection to be too "low" as it would cost a lot via AWS.  However, we would want a low caching period for low latency reporting