For making a true user experience in matter of Friendly URLs, I suggest making something like a plugin (maybe 2) which fires each time when the modContext->makeUrl() is called. By using it we shouyld have the possibility to change the behaviour of how makeUrl works - by this way we could extend by making our own method of encoding GET parameters (for example auto implementing the creation of URLs such as described here: https://forums.modx.com/thread/15058/ )