Trying to use with FlySystem (remote media via SFTP)

Please help, I'm trying to use IMCE together with media stored remotely but accessible with FlySystem via SFTP.

I'm able to successfully access files by url on my DEV host with /_flysystem/test-www/images/test.jpg but when I install and enable IMCE 8.x-1.5 on Drupal 8.3.3 it starts throwing the following error when I try to access /imce/test-www

Component\Routing\Exception\InvalidParameterException: Parameter "filepath" for route "flysystem.serve" must match ".+" ("" given) to generate a corresponding URL. in Drupal\Core\Routing\UrlGenerator->doGenerate() (line 202 of core/lib/Drupal/Core/Routing/UrlGenerator.php).
Drupal\Core\Routing\UrlGenerator->getInternalPathFromRoute('flysystem.serve', Object, Array, Array) (Line: 291)
Drupal\Core\Routing\UrlGenerator->generateFromRoute('flysystem.serve', Array, Array, 1) (Line: 105)
Drupal\Core\Render\MetadataBubblingUrlGenerator->generateFromRoute('flysystem.serve', Array, Array, ) (Line: 753)
Drupal\Core\Url->toString() (Line: 35)
Drupal\flysystem_sftp\Flysystem\Sftp->getExternalUrl('test-www://.') (Line: 67)
Drupal\flysystem\FlysystemBridge->getExternalUrl() (Line: 234)
file_create_url('test-www://.') (Line: 93)
Drupal\imce\Imce::processUserConf(Array, Object) (Line: 79)
Drupal\imce\Imce::userConf(Object, 'test-www') (Line: 31)
Drupal\imce\Imce::userFM(Object, 'test-www', Object) (Line: 24)
Drupal\imce\Imce::response(Object, Object, 'test-www') (Line: 35)
Drupal\imce\Controller\ImceController->page('test-www', Object)
call_user_func_array(Array, Array) (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 574)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 124)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext(Array, Array) (Line: 97)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}()
call_user_func_array(Object, Array) (Line: 144)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 64)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 57)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 99)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 78)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 50)
Drupal\ban\BanMiddleware->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 50)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 656)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)