Great!
For the grouped results I am afraid it is not going to work. When grouping is disabled, it can automatically load up more results – but not this way unfortunately.
Another option is to redirect to the search results page, but currently it will simply redirect to the same page and will do nothing.
Your best option here (if you want to keep the grouping) is to disable the “more results” feature, and increase the number of results displayed. The load more feature will only work if the grouping is disabled, but I don’t think you want that.