Migrating pages to flex-pages

When upgrading to the new Grav version from 1.6.x...can all existing pages be converted to flex pages or is there a lot of manually work to do?

There are over 1000 of modular pages in the project.

@christiana83, Not sure why you would want to do that... But, to be honest, I haven't spent much reading time on Flex Pages (not much docs anyway)...

According the 1.7 upgrade guide:

NOTE: Flex Pages feature is not yet used in the frontend of your site.

Then why the wish to 'migrate'?

Admin uses Flex Pages by default (can be disabled from Flex-Objects plugin)

For Admin, you apparently don't need to upgrade anything.

@pamtbaau, thank you for your answer. In Upgrade Info I found the following notice

"In Grav 1.7 we introduced Flex Pages as the new default page management UI. Also, to optimize performance, we stopped initializing pages on every admin call. Switching back to regular Grav Pages might temporarily resolve your issue. This is done by editing the FlexObjects plugin and disabling Pages (Admin) .

To properly address the issue, custom plugins should be updated to support both Grav Pages and Flex Pages by using PageInterface and also should expliclty Pages when required.

So I thought not to use flex pages will be a deprecated issue in next versions of grav and is an performance blocker in admin panel. The problem is that we really have a lot of pages.