Recursively remove .php .htaccess & Wordpress

I've set up a Wordpress site. I need to recursively remove the .php extension on files in a specific folder.

Say: www.domain.com/wordpresspage/ (set up with permalinks, all good).

I then need to remove .php recursively for folder: domain.com/gz/*

The content of domain.com/gz/ should have the .php extension removed. But only for this folder.

Folder structure

/
-/images (No .htaccess rules should apply, Wordpress takes care of it.)
-/downloads (No .htaccess rules should apply, Wordpress takes care of it.)
-/gz (.htaccess change, to remove .php file extension, overwriting Wordpress, in this particular folder)
-file1 (No .htaccess rules should apply, Wordpress takes care of it.)
-file2 (No .htaccess rules should apply, Wordpress takes care of it.)

Before I used the following .htaccess content to remove .php extensions, but now I need to only force this on one folder, since Wordpress is taking care of the rest.

#RewriteBase /
#RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /([^.]+)\.php\ HTTP
#RewriteRule ^([^.]+)\.php$ https://example.com/$1 [R=301,L]
#RewriteCond %{REQUEST_URI} !(\.[^./]+)$
#RewriteCond %{REQUEST_fileNAME} !-d
#RewriteCond %{REQUEST_fileNAME} !-f
#RewriteRule (.*) $1.php [L]

I've tried a ton of things already, but the last few included:

1. Use the old .htaccess file that removes .php on all pages. This solves my path issue, but gives internal server error on the rest of the site.
2. Tried a gazillion ways of filtering out that folder recursively, to the point I'm no longer sure if it's even possible. (Don't even remember a fraction of what I tried).
3. Tried in the permalinks to add .php - but since it will redirect to remove it again, I'll get yet another Internal Server Error.

TL;DR - Can I recursively remove .php on a specific path in my .htaccess file, so Wordpress ignores this folder and let's it deal with it's own business?

Added after first round of help, my .htaccess file now looks like this:

# -FrontPage-

IndexIgnore .htaccess */.??* *~ *# */HEADER* */README* */_vti*

RewriteEngine On
# Only apply if request starts with /gz/
# followed by at least one character and ends with .php
RewriteCond %{REQUEST_URI} ^/?gz/[^.]+\.php$
# Redirect to the same location but without .php ant the end
RewriteRule ^/?(.*)\.php$ /$1 [R=301,L]

# Only apply if request starts with /gz/ followed by at least one character
RewriteCond %{REQUEST_URI} ^/?gz/[^.]+$
# and the request it not a real directory
RewriteCond %{REQUEST_FILENAME} !-d
# and the request it not a real file
RewriteCond %{REQUEST_FILENAME} !-f
# Rewrite the request with .php at the end
RewriteRule ^(.*)$ /$1.php [L]

<Limit GET POST>
order deny,allow
deny from all
allow from all
</Limit>
<Limit PUT DELETE>
order deny,allow
deny from all
</Limit>

AddType application/x-httpd-php-old .php

<IfModule security_module>
  SecFilterEngine Off
</IfModule>
<IfModule security2_module>
  SecRuleRemoveByID 1-99999
  SecRuleRemoveByTag unoeuro
</IfModule>

After re-applying Permalinks, Wordpress adds this section to the .htaccess file:

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

Thanks in advance,

L