Benchmarking Ci4 router

Main problem for me in ci4 (or i cannot see the solution) is to use the router class and router collection as "subrouter" to split the routes
Scenario
Dinamic Front router (load routes from modules)
Controller
Method a
Method b
Method route
Another router and route collection instance

The handle () method should accept arguments handle(uri,method )
Checkroutes method should optionally detect language and passed as argument
Discover routes should take file array as arguments and should be public
getHTTPVerb and sethttpverb out and passed as arguments
A Cache routes (routescollection ?) Mechanism
Load cached routes array_merge routes without add every routes
Thanks .