Sweet deal! Don't make a speedbump out of this suggestion though. I'm a fan of pre-buffered replays (one of the few features that TF2 has that's absolutely solid) though I've only seen them in one game so far that I don't even bother to play anymore.
It seems like it'd be a pretty neat feature for moments like this:
"Oh man that play was awesome"
presses button saves demo of period of time to be recorded in OBS later
and/or
While commentating a match:
"Did you see that ludicrous display?"
presses button
(instant replay of action)
goes back to the live game
Starting to scrape the barrel here when it comes to features that may be desirable:
-Left/Right/Upsidedown/Backwards Handedness (Model)
For the handedness thing, I'm not even sure it applies but there may be some people out there that want their tachikoma to have a dominant hand.
-Toggleable Stopwatch/Timer in GUI
A timer/stopwatch (Think Starcraft 2) that can be included in the GUI might be too much information depending on if spawn waves exist or not so this one I'll field to you Justin before really going in depth about it.
-Team Isolated Chat During Rounds/Allchat Intermission
I'm going to go stick my neck out here and say I'm against trash talking in games. So this is an opinion thing. But I'm also not for making sweeping decisions while ignoring opposition to said decisions. I don't have conclusive data or anything but from the games I've played when you cannot talk to anyone but your team mates during an active round the likelihood of raging and people becoming incoherent sacks of anger decreases dramatically.
By having 'alltalk' only available during intermission and warm up type rounds when nothing is really on the line and you have time enough to waste trash talking I believe that players will have a much more positive overall experience while playing and be much less likely to be scared away from the difficulty that AoT will present to everyone.