VFS caching only for remote mounts on union

Is it possible to add an option so that VFS caching is disabled for local mounts on a union? Or in other words it directly grabs the file off the disk?

I have mixture of local & remote mounts, but since the local files are on an SSD and the cache is on the same ssd then it would be double caching with no benefit and create SSD wearing.

Not currently, but this is an often requested feature.

Looking forward to one day when it's implemented! Then I can just use rclone without mergerfs.

In the meantime, what is the best way around this? Is there a substantial loss of performance if I union and include a union?

e.g. union2=local1:local2:union1