It seems to me that the whole oathbreaker debuff is a solution looking for a problem. If the motivation to participate as a guide is to get the reward for being a guide, then if you don't get your seeker across the finish line you wasted your time. It's its own punishment. Assure that the motive for participating stays tied to completion and the oathbreaker debuff becomes moot. Place a penalty on players for disconnects that aren't their fault (at a time when connection errors and crashes are STILL unacceptably prevalent) and you're virtually guaranteeing that players gradually abandon the guided games function altogether and go back to posting "Sherpa requested" games on the100.