We want to cache bust on production deploys, but not waste a bunch of time off the bat figuring out a system for doing so. My thought was to apply a param to the end of css
In general this should be fine, but it's possible for this to not work if there is an intermediate cache (a proxy) that is configured to ignore the request parameters.
For example, if you are serving static content through Akamai CDN, it can be configured to ignore request parameters to prevent cache busting using this method.