Best practice multiple api filters with epics

[oli06]

This is more a question of "how to code" instead of an issue.

I got a view, very you can server-side filter a list. The filters are applied to a http.get request as URI-Parameters, e.g. https://example.com/data?name=ABC&range=25

For this request, there are three filters, which the user can apply to the search request. A name filter, a range filter and a category filter. I started implementing an EpicMiddleware the same way, as shown in the GithubSearch example. It uses a debounce time to wait till the user stops typing and then executes the search with all filters.
Because I use three different EpicMiddleware´s I also call a normal reducer function to update the search string in the redux store.

Example of NameSearchEpic (range and category filters are provided from the store, nameFilter comes from the action):

return Observable(actions)
        .ofType(TypeToken<NameFilterSearchAction>())
        .debounceTime(const Duration(milliseconds: 250))
        .switchMap((action) => _search(CompanySearchFilter(action.nameFilter, store.state.rangeFilter, store.state.categoryFilter)));

For the range filter I use again an epicMiddleware with a slightly shorter debounceTime but on the same time, the filter value should be updated instantly in the redux store because otherwise the Range-Widget would not be rebuild with the new value.

Example of the reducer function to instantly update the range value:

SelectCompanyViewModel _updateCompanyRangeFilter(
    SelectCompanyViewModel vm, CompanyFilterRangeAction action) {
  return SelectCompanyViewModel(
    categoryFilter: vm.categoryFilter,
    nameFilter: vm.nameFilter,
    rangeFilter: action.range,
    companySearchState: vm.companySearchState,
    categories: vm.categories,
  );
}

The third filter can`t be changed thus often and fast, has no debounce time and can be set on another page (No problems with that).

My questions are:
Is there a better way to use EpicMiddleware (e.g. one for all three filters) instead of using three different with three different actions?
Is it the right way to use a normal reducer function to update the filters?