As someone who frequently uses the feat/has its abruptly cancelled or bug out at the most inconvenient/critical moments, I can safely say this iconic ability is somehow even more difficult to keep functional with the arrival of new pathing, mob templates and pathing issues. It also flatout refuses to turn on sometimes.
But there's hope! I've seen the feat function more like its nwn2 counterpart on certain servers (as well as power attack) by remaining on (even during walking/movement shift) as a more polished/advanced toggle. Actually, why not just that the case for power attacks/dirtyfighting/flurry of blows to?
Advanced toggles for everyone!
It is possible to make walking no longer break combat modes.
We would like to tone down Improved Expertise before doing so. Otherwise the issue is players may simply travel with IE up in order to avoid ambush, which is undesirable.
What about if it simply gave other negatives? Especially if visible this gives a visual cue about the mechanical status.
-25% movespeed for Expertise, -50% for IE.
An "on guard" pose would also be amazing if it can be made to look decent, as some of the new combat animations do.
I personally believe expertise and similar feats are supposed to be portrayed as intense combat stances that sacrifice something to grant you something else.
It wouldn't make sense to me that you would be able to move around normally while hunched behind your shield facing the wind and naught else.
Due to the limitations of the engine these stances cannot be visually portrayed as far as I am aware.
Certainly there are many things that interrupt your 'Combat Stance' but that is realistic as well, if you have to chase an enemy you are literally running and can't keep up your positioning, if you are ensnared, or otherwise disabled you shouldn't be able to keep your 'Combat Stance' up, when you have no target at all.. What are you in a stance against? All directions? How?
Unfortunately in a low power setting like EFU, expertise and imp expertise are an 'easy button' for winning many small scale engagements and quests, I feel they are a bit too good as is.
If it was up to me expertise and improved expertise would only provide its armor class bonus against the enemy you are currently targeting and no other as their counterparts Power attack, Dirty Fighting, Flurry of Blows are only useful against what you are hitting with them.
Dwarven Defender of course is an exception, they are a PRC master of defense that exist as a living wall but even their defensive stance only gives 4AC (And other bonuses) but you cannot move whilst in it with a limitation to how many times a day you can actually use it.
Forcing deactivation once out of combat might resolve some of the woes of skipping around with IE up while also allowing PCs to click or use WASD to move around in combat.
Change Improved Expertise to function like Dwarven Defender and completely disable movement.
Without necessarily removing the feat or its utility, this drawback would be highly appropriate for "total defense" coward mode. Bunkering down. Holding a single spot.
In fact, while we're at it, can we limit Improved Expertise to a certain number of uses per day? Such that it has all the same limitations of the Dwarven Defender stance? That would make Stancebreach more effective against it, not effect Expertise (which uses a different mode), and likely remove all complaints related to its use.
Three uses of Improved Expertise per rest seems good enough to me.
I think combat modes should stick until they're toggled off because having to constantly reactivating them mid-combat seems extremely tedious and unfun.
If you want to tone down expertise then just make it function like it's PnP counterpart in that the bonus armor class you gain cannot exceed your base attack bonus, with no further nerfs. Maybe make it dodge bonus as well, I don't know what exact type of AC it is by default, so when people are caught flat-footed the bonus AC is negated if they're just idling or walking around in expertise mode.