how to change a way to set a cache's key

I set the route config as shown below code, when I want to open paths for default using '*' .

``` javascript
export const routes = [
{ path: '/', name: 'page-a', component: PageA, meta: { exact: true } },
{ path: '/b/:id', name: 'page-b', component: PageB },
{
path: '*',
component: DefaultComponent,
},
]
```
In general, all default paths share same component instance because router-view set key as router config's path.
Unlike general, on my business logic needs to make different instances for each default paths.
To make different instances, when I used router-view, I manually changed the key as shown below.

``` html

```

But router-multi-view seems no choice to change the way I set cache ( a bigCache in code) key manually,
but it provide only way I set cache key which is using parents's route path.

Is there another way to change way to set a cache's key.
And or how about add a way to set a cache's key through props?