High height and high risk aren't necessarily tied at the hip, at least up to the 3 or 4 foot range. Bad things happen when you roll the front tire off an elevated feature, but... for an experienced skinny rider, front tire position is nearly always a choice. You choose to correct balance with steering, and you can choose not to just the same. Loss of balance is felt well before a fall, at which point a rider can step off the bike and onto the skinny(between the front and rear wheels), and either a) salvage balance; or b) let the bike fall and locate a safe place to jump to. This assuming a wheelie drop or hop isn't a good option.
I disagree with the common notion that skinnies should be low & skinny OR high & wide. Low skinnies can be any width, but high skinnies? Wide ones invite inexperienced riders into a situation with a penalty for failure and an outcome they cannot control. Riders who are skilled enough to clean difficult skinnies are generally the same ones who can safely exit high ones.
As with many riding skills, like hopping or jumping, high skinnies should be attempted only after mastering several prerequisite skills (track stand; wheelie drop; hop; skinny exits from lower heights). Difficult skinnies are never 100% cleanable, but the outcome of failures can be controllable, with practice, 9X% of the time.
