mobile: let the user leave the web application to the native navigation application and have it return during a process

(Please edit the title if you have a better one)

Imagine a mobile web application, where the user needs at some point in a process to start the turn-by-turn navigation and then perform an action on the web application once it reaches its destination.

I see two possibilities:

1. Develop a step by step navigation by myself in the web application

For this I would like to go with the mapbox APIs.

Advantage:

  • The user stays in the application.
  • The flow is not interrupted.
  • It is more likely that the user will take the necessary actions once he reaches the destination

Disadvantages:

  • Need to develop the navigation system.
  • More expensive (mapbox plans)
  • Even if the personalized navigation could have a good quality, it probably will not exceed the implementation of Google

2. Open google maps from the web application

In fact, it is possible to simply navigate to the Google Maps website by passing some coordinates (Android will then automatically open the Google Maps application) or open the application from the browser for IOS users.
But in the other direction, I think it is not possible to automatically navigate to the web application (browser) when closing a native application.

Advantage:

  • No need to develop nav myself
  • There are no costs for navigation itself.
  • Probably better navigation system.

Disadvantages:

  • The styles do not correspond to the application
  • The user is removed the application
  • The user can not (return) finish the process as planned
  • One more click on the native application (maps) to start navigation
  • What happens if the user does not have the Google Maps application on their device (I am not sure that navigation is possible from the Google Maps website on the mobile device)?

I probably lost a few more points, but I think the decision is hard enough to make.

My question is, from a UX point of view, is it acceptable to let the user leave the application and wait for it to come back or is there another solution that I do not see?

One solution would be to send an insert notification and remind the user to finish the process, but push notifications are not really supported on the IOS website.

Also an argument by which the user could return is that he already made a certain amount of action during the process before starting the navigation and would probably be willing to end it, but there is still the possibility that he does not.

Any help would be greatly appreciated.