Shell - Flyout menu and tab menu relationship

I posted this last week but didn't get a response so just trying my luck again.

I am trying to create a flyout menu with 7 items, 4 of which are displayed as tabs on 5 of the 7 pages.

Trying to resolve this I have ended up with a huge AppShell.xaml file as I have a lot of repeated code, which I doubt is the way Shell is meant to be used. For example I have 7 menu items in the flyout, 5 of which have the same 4 bottom tabs on the page, so I have essentially copy pasted the below code 5 times, which seems incorrect?

     <flyoutitem A…>
            <tab ….. 1>
                <shellcontent >
            </tab>
            <tab ….. 2>
                <shellcontent>
            </tab>
            <tab ….. 3>
                <shellcontent>
            </tab>
       <tab ….. 4>
                <shellcontent>
            </tab>
        </flyoutitem>

     <flyoutitem B…>
            <tab ….. 1>
                <shellcontent >
            </tab>
            <tab ….. 2>
                <shellcontent>
            </tab>
            <tab ….. 3>
                <shellcontent>
            </tab>
       <tab ….. 4>
                <shellcontent>
            </tab>
        </flyoutitem>

In addition the other problem is that when I click on a flyout item, it loses track of highlighting the correct tab if you are on a tab page. I think this is due to each tab being linked to an individual flyoutitem.

So if I click FlyoutItem A, then click Tab 2,

The flyout is still highlighting FlyoutItem A, and does not highlight FLyoutItem B which is linked to Tab 2 that I clicked
Hopefully someone can point me in the right direction as to how I can correctly lay out this menu with shell?
Thanks!