Curious outsider here. So it appears that KSIQ had a .7 kw booster, lost the audio, had an STA for a 5 kw booster but the STA extension was dismissed on July 6? Forgive me for jumping in, but my interest is piqued because I operate a booster for one of my stations in the Pacific Northwest.
Yes, it is difficult to operate boosters when there are areas of signal overlap. You can sync all day long but the fact is that you will always have problems in areas where the signals are close in amplitude. The first trick is to locate the booster so as to minimize those areas, and the second trick is to adjust the delay to move the worst problems to areas of low population count.
In my rural market, I'm able to cover the primary population center very well with a well-placed single booster. I have a five-mile stretch of interference issues, which is mitigated by a translator which also helps with other signal-impaired areas.