This is common practice in the industry, the purpose is to save load time, it is just like the cache on your pc, windows does basically the same thing.   You should look into this  http://www.oxwall.org/store/item/579  instead of always having to change your dev mode.

Just remember if you use this cleaner try not to have your cpanel tabs on the same broswer as your site because it could end your sesson on the cpanel .  When i work online i have my cpanel on FF and then i work in the site on IE to prevent this, it just makes it easier especially if you are making tons of changes. 

If you prefer to use dev mode then i recommend having two entries, set one true and one false, and then just comment out the one you dont need.  Its faster and its easier to type // then take a chance on making a typo when you change one back a forth.

define('OW_DEV_MODE', false);

// define('OW_DEV_MODE', true);

Adding to what ross said +1 Ross

Andrew you are probably still asking yourself why they are the same.  One reason is that Oxwall may want to leave the door open for future changes.  For example, lets say that Oxwall decided to make those tpl files instead one day.  The foundation is  already there and without having to recreate the whole structure or change the flow they could do that much easier.

It is also much better to have the multiple layers which is why it is so common in the industry.  If someone might happen to somehow change your template files, since they may not be able to also clear your cache or access that second layer then their affect is moot.

IMO it is designed as a security obsticle as well as a platform for the posible future.

I hope that answers your question.  

Family, Marriage, and Dissatisfaction. Anthony, the protagonist of “Static,” is a man struggling to negotiate between what his family expects of him and what he wants out of life