I have an idea for the next EP iteration concerning replays and Aizamks UI. Would it be possible to make replays rewindable? So you can watch a specific thing several times in a row. Sorry if this is the wrong forum, dunno where to post this.
Unfortunately, this is technically impossible. First, you have to understand that a recorded game file is not a video, not even remotely. Think of it more like a log of what instructions happened in the match; "this villager was directed to build a house" and so on.
So, all that you have is this huge list of instructions saying who did what. And what happens when you are watching a recorded game? Well, the game is absolutely literally
being re-played, except instead of moving units around yourself, they are receiving instructions in sequence as read from the recorded game file.
At this point, you hopefully can see where this is going. There is no way to ever play a recorded game file as a video, because when it comes down to it, it is just a bunch of text instructions that don't mean anything outside of how the AoE3 game engine understands them and is able to re-play the whole match. The way "play fast" works is that it simply executes instructions from the log faster, based on how fast your CPU can handle running the game / executing game commands. The game engine cannot easily "rewind" a match to any custom point in time, as the only way to do that would be starting over from the beginning; reload the map and execute all commands which led to that desired point. And that is exactly what you have to do yourself now as well, just reload the rec from start; there is not really an other way. What we have done on EP is the addition of replay speed factor dropdown, which allows you to attempt to "overload" your CPU by a higher factor and possibly speed up command execution beyond what the regular game version offers - allowing you to get into a specific time point faster.