Nuxt SSR rebuild of routes.json on the fly (production)

I'm pretty sure the answer to this is no...but is there any way to initiate a rebuild of .nuxt/routes.json and .nuxt/router.js file on the fly, while the production server is running from within native nuxt functionality. nuxt.config.js router.extendRoutes builds the routes at the initial build time - haven't found a way of doing an update while the server is still running. Would prefer not to have to do a new npm build.

// Router middleware
router: {
    middleware: ['router-agent', 'ssr-promises'],
    async extendRoutes (routes, resolve) {
        // pulls in routes from external file
        await customRoutes(routes, resolve)
    }
},

We have a selection of custom routes we need to build from a CMS

// extendRoutes snippet
let pageRoutes = require('./routes-bkp.json')

try {
  const { data: { pages } } = await getPagesForRoutes.queryCMS()
  pageRoutes = pages
  console.log('Route Request Succeeded.')
} catch {
  console.log('Route Request Succeeded.!  Using backup version.')
}

pageRoutes.forEach(({ slug }) => {
  routes.unshift({
    name: slug,
    path: `/:page(${slug})`,
    component: '~/pages/_page'
  })
})

The purpose of all this is have a client build trigger in the CMS, when they update their pages.

More info about router.js here: https://nuxtjs.org/docs/directory-structure/nuxt

and about extending the router here: https://nuxtjs.org/docs/features/file-system-routing/#extending-the-router