How to manipulate with search data options

Question: Is it possible to show the products filtered by default on load by a certain taxonomy

Answer: yes, do next:

open your current theme file functions.php

on the same bottom of the file add next code

if (is_front_page())
{
    add_filter('woof_get_request_data', 'my_woof_get_request_data');
}

function my_woof_get_request_data($request)
{
    $request['product_cat'] = 'music';
    //$request['product_cat']='music,posters';    
    return $request;
}

if (is_front_page())

{

add_filter('woof_get_request_data', 'my_woof_get_request_data');

}

function my_woof_get_request_data($request)

{

$request['product_cat'] = 'music';

//$request['product_cat']='music,posters';

return $request;

}

Use comma if you need more welcome taxonomies

It is just an example-question, by your own logic you can always can add any data in search request ...

Remember: is_front_page() function doesn work in AJAX mode!

Example about how to show always 'In Stock products only' in the search results:

add_filter('woof_get_request_data', 'my_woof_get_request_data');

function my_woof_get_request_data($data){
    $data['stock']='instock';
    return $data;
}