It takes too long waiting for e107 to be perfect. Its power is in Admin UI, easy management data etc. So I decided and successfully tested to combine WordPress and e107. 

My favorite (and almost only used theme for WP is Impreza with Visual Bakery for building content), so I used this solution on my originally e107 site.

e107 is installed in a subdirectory (it works in the same level too, but I needed it this way to block access to this subdirectory. 

e107 site uses a custom plugin with a lot of data I need to manipulate with e107 way. Before it was a combination of the United Nuke and e107, but I need to remove Nuke soon because of PHP 8.

How does it work?  

- if prefix for e107 is f.e. e107_, then prefix for WP is e107_wp_ - so this way is e107 able to manipulate with WordPress tables. 

- include class2.php in wp_config.php with the correct path. In the beginning because of sessions. 

Then I created a WP shortcode in function.php and the content of it is fully managed with e107 handlers. I needed only one parameter to display the needed data. The reason is easy - I am more familiar with e107 programming than WP queries and posts and it is easier for me than write the same code in WP. 

I mapped this shortcode to Visual Bakery a and it is all.

Now I created posts/pages in WP, this solves URLs issues, SEO issues, easy content management issues, media management. And if I need to display data managed by e107, I just add a shortcode with the correct parameter.

And the power of Impreza grids, filters, content templates, and page blocks allows me to do exactly what I need - to be able to organize my collection the way I always wanted. And using e107 for managing data allows me to avoid WP administration. I still can't imagine managing this with WP and this is the perfect solution for me.  

Example:

https://www.kizi.sk/serie/gli-intrepidi-sir-condor/

The post itself is managed by WP, but everything below My collection is done by e107.