Finder class alias causes error

[Kirby]

Affected version

2.3.0

There seem to be some issues with XF::createAliasForClass()

ErrorException: [E_WARNING] Declaration of ClassAliasTest\XF\Pub\Controller\Forum::applyForumFilters(XF\Entity\Forum $forum, XF\Finder\Thread $threadFinder, array $filters) should be compatible with XF\Pub\Controller\ForumController::applyForumFilters(XF\Entity\Forum $forum, XF\Finder\ThreadFinder $threadFinder, array $filters)
src/addons/ClassAliasTest/XF/Pub/Controller/Forum.php:0

I've attached the whole Add-on, it's basically just

namespace ClassAliasTest\XF\Pub\Controller;

class Forum extends XFCP_Forum
{
    protected function applyForumFilters(\XF\Entity\Forum $forum, \XF\Finder\Thread $threadFinder, array $filters)
    {
        return parent::applyForumFilters($forum, $threadFinder, $filters);
    }
}

to demonstrate the issue.

I can reproduce this on 2.3.0 and 2.3.2 with PHP 7.2 and 7.3; PHP 7.4+ seems to be fine.

While I luckily don't have to use PHP 7.2 / 7.3 and could probably work around this issue, it would be nice if it could be fixed.