It's done. This code will be available in the next version:

function __construct() {
	add_action( 'wpforo_after_init_folders', function( $folders ) {
	$cache_dir = apply_filters('wpforo_cache_dir', $folders, $folders);
			

You can use this hook for it, but not that the function in it is an example, code that would crush the page but show the cache file path, so you need to manage it by your needs.

Please note. We don't know if this will work without problems.

add_action( 'wpforo_after_init_folders', function(){
    //var_dump(WPF()->folders);
    //die;
} );

but we don't have any option to do anything.

I modified : wpforo\classes\Cache.php

Added: 

$cache_dir = apply_filters('wpforo_cache_dir', $folders, $folders);

function __construct() {
   add_action( 'wpforo_after_init_folders', function( $folders ) {
      $cache_dir = apply_filters('wpforo_cache_dir', $folders, $folders);

How does the forum work with disabled cache?

we don't have any option to change the folder of the cache.

I see you don't but are you saying as plugin authors you can't create such an option or you won't create such an option? 

Looking in the Cache class in the plugin it doesn't seem overly difficult to change this to another location but because its (all the filters) are wrapped up in the class and can't be accessed from another plugin / theme it seems impossible to modify this without modifying the core files in your plugin. 

I will check for the ability to exclude paths in S3 Uploads plugin but to my knowledge they don't have this but I will go investigate. 

EDIT: Just checked they state there is no method of excluding a path and you have to change the path on the thing trying to store files. So I guess this is an incompatibility with your plugin and S3 then as far as cache goes. 

We understand the issue, but the problem is that we don't have any option to change the folder of the cache. 

Can you check, maybe, there is an option to exclude a folder? If no, please contact the creators with the issue. 

I'm sorry but we can't do anything from our side.