Q:

Comunication between webview and main window without remote module

Is there a way to communicate between the webview and the main window without enabling the remote module ? 
<webview src="http://www.google.com/" enableremotemodule="false"></webview>

When this attribute is false the guest page in webview will not have access to the remote module.  The remote module is avaiable by default. 
https://electronjs.org/docs/api/webview-tag#enableremotemodule

A:

Not quite what you asked but I took heed of the Electron team's warning and opted to use iframes rather than webviews

We currently recommend to not use the webview tag and to consider
  alternatives, like iframe, Electron's BrowserView, or an architecture
  that avoids embedded content altogether. 

I've had success using Window.postMessage() but I am far from an "expert" on any of this. 

The window.postMessage() method safely enables cross-origin
  communication between Window objects; e.g., between a page and a
  pop-up that it spawned, or between a page and an iframe embedded
  within it.