SnappyMail does not work

[hifihedgehog]

See the-djmaze/snappymail#525. Per @the-djmaze's direction, I made some changes to get SnappyMail to work. Namely, I deleted the .htaccess file that optimizes SnappyMail for fast load times with precompressed files. I would like to serve these files and that requires .htaccess. See below for more details.

[hifihedgehog]

With @the-djmaze's help, I was able to pinpoint the problem file which is .htaccess located under the directory public_html/snappymail/v/2.N.N/static/. The file contents are so:

<IfModule mod_headers.c>
	<IfModule mod_rewrite.c>
		RewriteEngine On

		RewriteCond %{HTTP:Accept-encoding} br
		RewriteCond "%{REQUEST_FILENAME}\.br" -s
		RewriteRule "^(.+\.js)$" "$1\.br" [L,T=application/javascript,QSA]

		RewriteCond %{HTTP:Accept-encoding} gzip
		RewriteCond "%{REQUEST_FILENAME}\.gz" -s
		RewriteRule "^(.+\.js)$" "$1\.gz" [L,T=application/javascript,QSA]

		RewriteCond %{HTTP:Accept-encoding} br
		RewriteCond "%{REQUEST_FILENAME}\.br" -s
		RewriteRule "^(.+\.css)$" "$1\.br" [L,T=text/css,QSA]

		RewriteCond %{HTTP:Accept-encoding} gzip
		RewriteCond "%{REQUEST_FILENAME}\.gz" -s
		RewriteRule "^(.+\.css)$" "$1\.gz" [L,T=text/css,QSA]

		<FilesMatch "(\.js\.br|\.css\.br)$">
			SetEnv no-gzip 1
			SetEnv no-brotli 1
			# Serve correct encoding type.
			Header append Content-Encoding br
			# Force proxies to cache brotli &
			# non-brotli css/js files separately.
			Header append Vary Accept-Encoding
		</FilesMatch>

		<FilesMatch "(\.js\.gz|\.css\.gz)$">
			SetEnv no-gzip 1
			SetEnv no-brotli 1
			# Serve correct encoding type.
			Header append Content-Encoding gzip
			# Force proxies to cache gzipped &
			# non-gzipped css/js files separately.
			Header append Vary Accept-Encoding
		</FilesMatch>

		<FilesMatch "(\.js\.br|\.js\.gz)$">
			Header set Content-Type "application/javascript; charset=utf-8"
			ForceType application/javascript
		</FilesMatch>
		<FilesMatch "(\.css\.br|\.css\.gz)$">
			Header set Content-Type "text/css; charset=utf-8"
			ForceType text/css
		</FilesMatch>
	</IfModule>
</IfModule>

If I delete the .htaccess file, SnappyMail miraculously works. However, it should work without deleting this file. Technically, OpenLiteSpeed now supports .htaccess files but it does so with changes. Ideally, I want to use it so I can serve the precompressed files. How could this .htaccess file be made to work within the constraints of OpenLiteSpeed?