It bothers me that data latency is an issue in this situation. The main problem I see is network hubs going down or your clients having modem lines instead of fiber. You're going to have data latency issues, whether you build them into your system or not. It takes time for data to move from client site to your site and back to client site. There is no 1 second magic bullet, no matter how hard you look for it. There's gonna be lag.

You can't promise instantaneous responses because you don't control all the environments and the data is spread out so far between clients. And if you try to promise it, and don't deliver, that's going to make your company take a serious reputation hit.

Talk to your bosses. Make it clear that no matter what solution is implemented, that data latency of some sort will be a real, and uncontrollable, issue.