I tried using version 3.0.1, and this time it gets further to actually creating the forum, but when it tries to migrate topics I get this error:

Fatal error: Uncaught Error: array_merge(): Argument #2 must be of type array, bool given
in /www/sitename/public/wp-content/plugins/go2wpforo/boards/bbpress.php on line 118

Call stack:

1. array_merge()
   wp-content/plugins/go2wpforo/boards/bbpress.php:118
2. go2wpforo\boards\bbpress::get_sticky_topicids()
   wp-content/plugins/go2wpforo/Main.php:596
3. go2wpforo\Main::do_topics()
   wp-content/plugins/go2wpforo/Main.php:1308
4. go2wpforo\Main::do_actions()
   wp-includes/class-wp-hook.php:310
5. WP_Hook::apply_filters()
   wp-includes/class-wp-hook.php:334
6. WP_Hook::do_action()
   wp-includes/plugin.php:517
7. do_action()
   wp-content/plugins/wpforo/wpforo.php:515
8. wpforo\wpforo::init()
   wp-includes/class-wp-hook.php:310
9. WP_Hook::apply_filters()
   wp-includes/class-wp-hook.php:334
10. WP_Hook::do_action()
    wp-includes/plugin.php:517
11. do_action()
    wp-settings.php:632
12. require_once()
    wp-config.php:57
13. require_once()
    wp-load.php:50
14. require_once()
    wp-admin/admin.php:34

I deleted the following code from the public function get_sticky_topicids() { function in bbpress.php and it's now successfully importing topics.

Process is still underway, but as far as I can tell the only thing I'll miss out on is sticky topics by removing this code.

$sql             = "SELECT meta_value AS srlzs FROM " . $this->db->postmeta . " WHERE meta_key = '_bbp_sticky_topics'";
		if( $srlzs = $this->db->get_col( $sql ) ) {
			foreach( $srlzs as $srlz ) {
				$sticky_topicids = array_merge( $sticky_topicids, unserialize( $srlz ) );
			}
		}