We pick alternative locations for altimeters.  The standard top of the hand/wrist mount is a real snag hazard. We try to pick the most snag free mounts as well.  A pillow mount on the chest strap and soft mudflap mount are great options.  The carbon fiber mudflap mount is too rigid, it can snag and rip canopies.  While normal hand mount altimeters are a no go, the low profile elastic wrist/forearm mounts are ok.