If you aren't already using the mover tuning plug-in, now is a good time to have a look at it.
The latest update allows per-share settings override for detailed control over how your caches are used.
I use this plug-in to keep files in cache based on their age, so for example in a media server, you can have the last 14 days of TV shows kept in cache, while still running the mover regularly.
It can also do a full move if the disk is above a certain threshold value, so if your cache is getting full, it can dump all files to the array as per normal.
So you always keep the most important recent files on the cache, with a greatly reduced risk of running into a full cache issue and the problems that causes.
Now, with the latest update, you can tune these settings PER SHARE, rather than being across the whole system.