Description of Lynk V1 update for V2 users
What is the difference between V1 and V2?
Page builder
The elementor page builder is easier than an existing page builder, and is easy to customize for beginners. You can easily add by drag and drop and you have the option to customize various designs. We updated the core to make it easier to use the elemtnor page builder, making it easier to customize than before and to use more features.
In V3, you have to hard-coding to do customization. But now you can customize it with the elementor page builder, without having to modify the source code. And you can customize more parts. (Listing detail page, each page, post page, map page, archive, header, footer, etc ..)
source code
In V3, the old method and the source code were renewed in the latest method. So in V4, the theme is faster than V3 and there is less conflict with 3rd-part-plugins.
Some cool features that have been updated from V1 to V2

You can freely customize it, use different headers for each page you want, and use global headers to share common headers.

You can customize more freely than before and you can see what you want in the footer.
You can freely customize colors, menus, and locations.

In the past, only a few layouts were available, but you can create your own listing detail page with your customized custom and use the customized listing detail template.

Previously, you needed addons to modify the Map location, but now you can modify the Map location without addons. (Some options require an addon.)
You can add a map to a location you want, or you can remove a map and use it as a List page.

Previously, V3 only supported the archive page for the listing category. But now you can create your own archive page and customize it.

In previous versions of V3 you needed a hard coding technique to customize the source or code of the files to modify the module, but now you can customize the location, view meta values, and design in the page builder.

In V4, we have created a post submit page with many clients’ requests.
Now you can easily create a post submit page using short code.

How to update Themes, Step By Step

No, V2 is not designed by Visual composer. V2 is by Elementor page builder.

It gives you more ability or options to modify your site by live page builder.

Unfortunately, it is impossible.
You need to set a new page.
However, the elementor page builder can be drag & drap and easy to customize.
So you can quickly set up your new page.

You can import demo data and change them. Listings, posts will not be disappeared.

Unfortunately, you need to do by Elementor. 
We wish we could provide you a migration tool. But these are totally different. 
We didn’t have a plan to add this new Elementor version. We found it’s much advanced and potential to build your own site. That’s why we added for our clients and spent double time than just a single theme.

We also created demos which are mostly same as the old version. We believe it helps you to have similar layouts, design you have now.
So, if you want to move to the new version, you can import new demo data and customize them to closed to your design.

If you want to stay V3 with visual composer, you can stay.

If you have a test site, a local site or a multi site, you can simply install it and import demo data.
Many of our clients love the new features and moved to the new version after having a test.