Super LTTP on this one, but AIlile and I got around to giving the changes a whirl.
The delay in moving gems is significantly more noticeable when playing using AP Mode then with Timer mode. Perhaps this a result of AP Mode needing to check/report the state of the game board after every gem move, versus Timer mode only needing to resolve the state of the game board after the timer expired?
For most players, the delay shouldn’t be much of an added inconvenience. For more nimble players, the added sync lag is annoying because the lag time is generally greater than the time that such a player needs to move the next gem. This results in gem moves not being recognized by the game, while the move timer still is running, which is frustration central. Would not recommend using Timer mode in Co-Op play.
And… it wouldn’t be a co-op post from me without some crash codes, so… 
We had some consistent crashes during Co-Op runs. Strangely though, the crashes did not occur during the rounds themselves, but during resolution of the after-battle chests themselves.
A selection of some of the crash codes:
As far as we can ascertain:
- These crashes appear to be attributable to the server processing resolution of the end-of-battle treasure chest.
- It seems that one player can open the chest without issue, but then the other player crashes out (I opened the chest first, causing AIlile’s crashes in screenshots 2 and 3 when attempting to action the chest. For screenshot 1, I observed her opening the chest without issue and then I crashed out before being able to action the chest).
- The crashed player drops group and is returned to the Tavern upon restart. The received chest is then actionable as normal per being placed in a blank chest slot of requiring immediate overflow resolution.
Possible attempts by server to incorrectly sync individual chests as if they were one chest (crash being cause by a player attempting to open a chest a server believes has already been opened)?
Group was private (may be a confounding issue or cause), there were no other players in the party. Dungeons run were Wyrmhelm and Pharos of Lothdyn, Difficulty 2.