"The second issue is that the cavalry groups around here discourage extra equipment attached to the saddle because the more stuff attached to a saddle, the more likely the trooper can become entangled when they need to dismount in an emergency."
Huh? Having been on both Morgan's Raids (campaign rides of 60 miles in 4 days) which had a ton of Eastern reenactor cavalry, I find this statement a bit nonsensical. Artillery valises are a moot point as your rarely see mounted drivers guiding caissons and limbers over hill and dale in reenacting. Valises were used by mounted officer's (not troopers) in all branches of service during the ACW, and are used, at least out here, by our officer's with their Grimsley saddles and fanciful shabraque. As Captain and above Officer's don't often dismount to fight on foot, and don't carry a carbine (which is a BIG source of dismounting\thrown entangelements) we don't worry much about the valise
I ride with Terry Crowder at all the big events, he always has a valise and a sword, and never has become entangled with the valise that would have endangered him.....
Truth be known the reason you probably don't see valise's is
a) don't need 'em (you don't carry all of your stuff during a reenacting day on your horse, you simply go back to your tent) b) money (plenty of other things to buy at ALL times as a horse owner)
c) start out with the basic's and don't buy all of the 'extra's'....crupper for example (issued to all federal mounted troops, rarely seen in reenacting).
d) the impression didn't use valises (trooper, bugler, teamster....)