Help! losing custom styles on a webblock after publish

Ok so the situation is that I needed to rapidly build a very specific webblock that became a centerpeice for a major demo - We have quite a large application and and it is seperated into many different categories, so making the style in the theme with classes was not feasible at the time due to the specific requirements and need for rapid turnaround on changes. I had to use the style editor to implement the changes and redoing them all in the theme module is going to be a nightmare, but in the meantime, randomly when i update modules that reference this block, I lose all my custom CSS and have to copy the old block back into the application.  It happens about half the time and we have a live version of this that needs the webblock - I am in the process of creating classes for the styles to solve this but due to the size of our overall solution i need a full day to accomplish this.  Is this a known issue, and also is there anywhere I can see all the custom styling to move over more quickly than going through the block visual editor tree one by one?  

Hi Andrew,

Are the classes you define in the web block "lost" or overwritten by consumer module classes? The precedence is defined by the order of the load, that may not be obvious.

Please check