Due to PHP Bug #53727, is_subclass_of might return inconsistent results on some PHP versions if \Illuminate\Contracts\Support\Renderable::class can be an interface. If so, you could instead use ReflectionClass::implementsInterface.
Due to PHP Bug #53727, is_subclass_of might return inconsistent results on some PHP versions if \Encore\Admin\Grid\Simple::class can be an interface. If so, you could instead use ReflectionClass::implementsInterface.