I don't know if you noticed, but a low frame rate seems to affect differently units movements, and construction times. Units seem to move per time. So in case of a low frame rate we just miss part of their journey, but they reach their destination accordingly. On the other hand, with a low frame rate constructions seem to hold on forever. Lower the frame rate, longer the construction time of all the buildings. Perhaps it does worth a check.
The simulation is running on the server and runs at a solid 30fps because its not rendering units's and structures, its running the game but not drawing it, your pc draws the action. Your pc is just rendering all the action being streamed from the server. so even if you drop out of a match and rejoin , everything still runs on the server. Best test is to play an AI match, then build a massive base, when your commander starts construction on the first structure, exit the match using alt-F4. restart PA and sign in, it should ask if you want to rejoin the match. When you re-join you will notice your commander has continued to build the base you started while you were disconnected. This explains why you see things happen like you explained in the above post, when your pc lag's either from FPS drop or network lag/packet loss (I use crap quality 3g internet ) you will notice freezing in game-play but the game continues in the background on the server at a solid 30FPS (Unless the AI bug's out).
You can even uninstall the entire game during a game, run ccleaner, restart, reinstall and rejoin and continue the game. I have noticed that performance drops when you give units commands that causes them to do things, to the point you can't play anymore and then stop it and everything runs a lot smoother instandly. I heard that game crashing macro-keys excist.
