Your question is very important to me also. Since I have been researching a lot on Coptic chant and all my research leads to the Syrian system, it's strange that we are so isolated from each other. I also agree that Copts are mostly isolated from the Armenian Church than the Syrian, Ethiopian and Eriterean Churches simply because of geography and cultural boundaries. But the Armenian contribution to the Coptic Church is well documented. The more I research Coptic studies, the more I find interconnections with the other OO communities. There is so much interconnection with the other OO churches, it would take a life time to appreciate them.
This doesn't mean we don't have real differences in our music, history and culture. Some of these differences are very hard to accept. We all live in our cultural bubbles. Any small change in our bubble causes controversy. Just look at language usage. The Coptic bubble in the diaspora (especially the US) is different than the Coptic bubble in Egypt regarding the use of the Coptic language. Then there is a difference between first generation Coptic Immigrant bubbles to second generation Coptic bubbles regarding the use of the Coptic (and Arabic) language. There is so much controversy that results because we simply don't want to leave our bubble. How much more divergent would the cultural bubble be if we take a sneak peak at the Armenian or the Ethiopian bubble? We naturally compare it to our own experiences and immediately reject the differences (even if there is no logical reason to do so).
How do we fix this? As you alluded to, it depends on where you coming from. Trying to change much in a small conservative group is going to be different than trying to bring about change in a progressive, ecumenically-driven community. It all starts with attitude. First we need to examine our bubble and see what things must remain and what things are useless appendiges in that bubble. Then we need to see if we can simply get rid of ethnic egoism and open the bubble (and our minds) to ethnically divergent brothers and sisters. It's a personal individual decision before it becomes a community's decision.