I apologize the delay here
I will make a example below of manual code and code produced with a possibly minimal Layout (not using a Child Layout, just one single layout):
Manual to your template:
<footer class="row" >
<div class="container-fluid" >
<section class="container-fluid" style="background-color:red;" >...</section>
<section class="container-fluid" style="background-color:blue;">...</section>
</footer>
It is not possible to make that with Layouts as you will have a ROW each section, instead of just section, or a double section if you class the Row as section (and the "holded" cell too)
The above HTML (coded directly in a php template) produces this HTML:
<footer class="row">
<div class="container-fluid">
<section class="container-fluid" style="background-color:red;">...</section>
<section class="container-fluid" style="background-color:blue;">...</section>
</div></footer>
With the Layout, you have something similar to this HTML:
<footer class="row">
<div class="col-sm-12 container-fluid">
<div class="row">
<section class="col-sm-12 container-fluid">...</section>
</div>
<div class="row">
<section class="col-sm-12 container-fluid">...</section>
</div>
</div>
</footer>
It is clear that if it's coded manually it's very "raw" and you get what you code, not a single thing more.
What you code with a tool (in this case layouts) it is different - it is impossible to cover all the possible cases of nesting with a tool, unfortunately.
The GRID (Layouts) has that structure.
You can code manually and have exactly the structure you want, but that's a different thing, also in terms of time.
We try to give the best possible approximation that lets you build things quickly, those are the possibilities you have to build 100% row with nested structure inside.
A tool (in this case Layouts) gives always a set of "limited" possibilities, which are not present in a manual code where you go in and edit Code manually.
In regard to the functionality, and the time, with Layouts we provide a possibility to do this quickly and no manual code.
Unfortunately it also restricts us to certain output scaffolds.
I apologize this inconveniences, but unfortunately I can not change this in Layouts, as it is built by default that way.
That said, you could achieve exactly the structure you want by using the Child Layout rendering and adding an additional wrapper to the 2 rows using our API Filters:
apply_filters( 'ddl_render_row_start', $markup, $args );
apply_filters( 'ddl_render_row_end', $markup, $args );
In "args" you have all the necessary info to know with what your' dealing and in "markup" you could append the additional element you want to achieve the structure shown.
https://toolset.com/documentation/user-guides/layouts-framework-api/
Please do not hesitate to open a new thread if other issues or problems arise
Thank you for your patience.