Add another exception to htaccess? - .htaccess

Question

My .htaccess file alows access to real files & folders on the server. For anything else, it will redirect to /index.php, except when the app folder is specified in which case it will redirect to /app/index.php. I want to add a second folder named appbeta which will redirect to /appbeta/index.php. How should I modify my .htaccess to add this additional exception?
SetEnv APPLICATION_ENV development
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(?!app)(.+)$ /index.php?u=$1 [NC,QSA,L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^app(.+)$ /app/index.php?u=$1 [NC,QSA,L]
RewriteCond %{REQUEST_FILENAME} -s [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^.*$ - [NC,L]
RewriteRule ^.*$ index.php [NC,L]

Answer 1

I am not exactly sure what the following rewrite does:
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(?!app)(.+)$ /index.php?u=$1 [NC,QSA,L]
However, if your current .htaccess is working as you want, I would try the following which puts a rewrite for /appbeta right before the rewrite for /app:
SetEnv APPLICATION_ENV development
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(?!app)(.+)$ /index.php?u=$1 [NC,QSA,L]
# rewrite /addbeta to /appbeta/index.php ...
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^appbeta(.*)$ /appbeta/index.php?u=$1 [NC,QSA,L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^app(.+)$ /app/index.php?u=$1 [NC,QSA,L]
RewriteCond %{REQUEST_FILENAME} -s [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^.*$ - [NC,L]
RewriteRule ^.*$ index.php [NC,L]
note: no new question started as mentioned in comments, fix above (change ^appbeta(.+)$ to ^appbeta(.*)$)