The idea was to create a Taser system that could be effective in the intermediate range (30-100 feet) where a regular handheld Taser could not reach, but from which thrown projectiles could still be a viable threat against someone.
Ultimately, the project was a commercial failure, primarily because of the cost of the cartridges. At something like $125 each, they were nearly five times the cost of regular Taser ammunition.
I don’t believe these saw much use. They’re discontinued now I believe. In part due to their expense.
I’m not sure if your 10% is just an estimate or if you’ve found a study on these. But one driving perspective for less lethal devices is for them to be used instead of lethal force. There’s also the inverse where they are viewed as a tool that enables a level of force that may be engaged for less dire scenarios. The latter may be used to justify force that wouldn’t have otherwise been applied, but the former seeks to reduce harm when a degree of it is deemed necessary.