How to make a unique footer follow content?

I have very recently discovered Latex while trying to write consistently edited monthly technical reports for my customer.

Problem: how to make the footer change to a predetermined text based on the content of the page, especially when the content occupies partial and not whole pages.

More details: There are three different legal statements that I have to choose from, depending on the material on the page/pages to stick in the footer.

So far I have tried: fancyhdr package and created four pagestyles. To start off I set the global header footer. This works just as expected, all pages get the same header and footer. For material that needs one of the three legal statements I use thispagestyle and pick one of the custom defined page styles to change the footer through a pagestyle. As you can already guess, when the content is say, 1.5 pages long, I get the desired footer on the first page where the paragraph appears, then it reverts to the global footer on the next page.

Desired behavior would be let the second page also have this footer, and change back only on the third page.

I am using documentclass article. No specific reason to pick it, other than copy pasta from the internet. Not knowledgeable enough to pick the correct one.

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Edit 2020-11-05: Sample Code to recreate the problem:

documentclass[12pt, letterpaper]{article}
usepackage{graphicx}
usepackage{geometry}
pdfpagewidth=paperwidth
pdfpageheight=paperheight
usepackage{lipsum, blindtext}
usepackage[T1]{fontenc}


%%% HEADERS & FOOTERS
usepackage{fancyhdr}

%pagestyle{fancy}

%
fancypagestyle{nolegal}
{
    pagestyle{fancy}
    fancyfoot[L]{}
    fancyfoot[C]{}
    fancyfoot[R]{thepage}
    %footskip=30pt
}

fancypagestyle{legal1}
{
    pagestyle{fancy}
    fancyfoot[L]{}
    fancyfoot[C]{legal 1 Applies to Content}
    fancyfoot[R]{thepage}
    footskip=30pt
}
pagestyle{nolegal}

begin{document}
    textbf{(No special legal applies)}
    lipsum[1-6]
    
    textbf{(Begin legal 1)}
    thispagestyle{legal1} % Also tried pagestyle{legal1} [Line 40]
    lipsum[1-6]
    newline
    textbf{(End legal 1)}
    
    % If switching page style in line 40, switch back with pagestyle{nolegal}
    lipsum[1-3]
    
end{document}

As expected page 2 generated by this sample gets the statement in the footer correctly. However, it gets removed on page 3.

documentclass[12pt, letterpaper]{article}
usepackage[headheight=14.5pt,footskip=30pt]{geometry}
usepackage{lipsum}
usepackage[T1]{fontenc}

usepackage{fancyhdr}
%pagestyle{fancy}

fancypagestyle{nolegal}
{
    pagestyle{fancy}
    fancyfoot{}
    fancyfoot[R]{thepage}
}

fancypagestyle{legal1}
{
    pagestyle{fancy}
    fancyfoot{}
    fancyfoot[C]{legal 1 Applies to Content}
    fancyfoot[R]{thepage}
}
pagestyle{nolegal}

begin{document}
textbf{(No special legal applies)}
lipsum[1-6]

textbf{(Begin legal 1)}pagestyle{legal1}
lipsum[1-6]
newline
textbf{(End legal 1)}thispagestyle{legal1}

pagestyle{nolegal}
lipsum[1-3]
end{document}

documentclass[12pt, letterpaper]{article}
usepackage[headheight=14.5pt,footskip=30pt]{geometry}
usepackage{lipsum}
usepackage[T1]{fontenc}

usepackage{fancyhdr}
pagestyle{fancy}

fancypagestyle{nolegal}
{
    fancyfoot{}
    fancyfoot[R]{thepage}
}
fancypagestyle{legal1}
{
    fancyfoot{}
    fancyfoot[C]{legal 1 Applies to Content}
    fancyfoot[R]{thepage}
}
pagestyle{nolegal}

newcommand*legalpagestyle{}
newenvironment{legal}[1]
  {parxdeflegalpagestyle{legal#1}pagestyle{legalpagestyle}}
  {thispagestyle{legalpagestyle}par}

begin{document}
textbf{(No special legal applies)}
lipsum[1-6]

begin{legal}{1}
textbf{(Begin legal 1)}
lipsum[1-10]
newline
textbf{(End legal 1)}
end{legal}

textbf{(No special legal applies)}
lipsum[1-3]
end{document}