Dashboard design with sections

I am considering to migrate my current wall tablet dashboard to sections mode.

The current dashboard is made by a left menu, 25% of the screen, and 75% on the right for the contents.


This sizing done with the lovelace-layout-card.

By moving to sections view, I set the max colums to 4 and the idea was to set the left panel section large 1 column, and the right body large 3 columns to replicate the 25-75% proportions.

The issue is that if i set them 1-3, the right body is moving below, not on the right.
If I set it to 1-2, they are correctly displaying one next to the other, but without the 25-75% proportion I’d like to have.

As you can see the proportions are different compared the first image that is the current dashboard.

I do not fully understand the logic of the sections view, any suggestion ?

Second question: I don’t like the way I am making my dashboard change views, actually I had to copy it to other dashboards where I just change the body. So when I click on an item in the left menu, I simply make it navigate to another dashboard. This means that I have to maintain multiple dashboards, if I change something in the menu, I have to change it in every dashboard.
Is there any way to create a fixed menu and only changing the body content ?
I thought I might be doint that with Visibility, so when I click on a menu item, it changes a selection helper that is used for the visibility of the body pages. But I don’t like this because in the backgroung I would have an huge dashboard loading.
Is there a way to have sort of 2 frames, left side with a dashboard containing only the menu and when I click on an item, it will load another dashboard in the right frame ?