[5.3] Disable gzip compression of files in Release/ folder

No, there is no way to disable this (unless you make a development build). You can probably find the uncompressed files in the Temp folder of your project after the build, though.

What is your use case?

 

As for "It's weird to assume everyone using WebGL build target is distributing the files just the way you have imagined." - there may be many different ways you can distribute the files, but there are also many people who have been running into issues setting this up in the past - so the reason with the changes in 5.3 (where we no longer output uncompressed files) is to have a setup which provides reasonable results in most cases, without requiring everyone to read their web server manual first. I'd argue that this may be the single biggest cause of user confusion pre 5.3. The main thing about 5.3 is, that when the server is not configured to reroute to the compressed files, the JS code will fall back to downloading the gz files and decompressing them in software.

This solves the following:
-When outputting both compressed and uncompressed files as before, we have had to constantly answer the question of "Why is my build XXX MB?" as people would not read the docs.
-When outputting both compressed and uncompressed files as before, we have had to constantly answer the question of "How do I set up my XYZ web server?" - for which the answer would typically be "Sorry, we don't know either".
-The Apache rewrite rules are merely a hint, which sets up compression for apache when the user happens to use Apache. For other servers, you can still use other setup, or fall back to having Unity decompress the files itself in JS.

Also note that when you have the server compress files for you instead of using pre-compressed files, we have seen this lead to servers overloading on CPU resources and dropping requests because of this (this may not be true for your setup, just something to consider, as we've seen this happen before).

All that said: I understand your use case - and yes, in such a case an option to disable compression for release builds may make sense. We'll gather more feedback and consider it.