k8s gateway API regression downstream is caused  by first scenario, following scenarios are dependent on ability to create the K8sHTTPRoute in kiali. I was unable to do so manually - first test scenario goes like :

 
Scenario: Create a K8s Gateway API Routing scenario
When user opens the namespace "bookinfo" and "reviews" service details page
And user clicks in the "K8s Gateway API Routing" actions
And user sees the "Create K8s Gateway API Routing" wizard
And user clicks in the "Request Matching" tab
And user clicks in the "headers" request matching dropdown
And user types "end-user" in the matching header input
And user clicks in the "Exact" match value dropdown
And user types "jason" in the match value input
And user adds a match
And user clicks in the "Route To" tab
And user types "100" traffic weight in the "reviews" workload
And user clicks in the "Route Filtering" tab
And user clicks in the "requestMirror" request filtering dropdown
And user adds a filter
And user adds a route
And user previews the configuration
And user creates the configuration
Then user sees the "Istio Config" table with 1 rows

• Service Details Wizard: K8s Gateway API Routing.See a HTTPRoute generated
• Service Details Wizard: K8s Gateway API Routing.Update a K8s Gateway API Routing scenario
• Service Details Wizard: K8s Gateway API Routing.See a K8s Gateway generated with warning
• Service Details Wizard: K8s Gateway API Routing.Delete the K8s Gateway Routing scenario

 scenarios mentioned above are passing on the upstream