Have you ever packed a schute?
Nobody who packs parachutes calls them 'schutes' so I'm going to go out on a limb and guess you are not a rigger or even a sport jumper
Because everyone knows that parachutes are ejected with explosive charges, or in the more modern versions, a bottle of compressed air.
No, sport parachutes are deployed by hand either with a pilot chute deployed by hand or by a spring loaded pilot chute deployed by a ripcord. There is an automatic activation device for the reserve parachute that uses a small pyrotechnic charge inside a cylinder that propels a cutter to sever a fabric closing loop that allows a spring loaded pilot chute to deploy.
I have gone skydiving, and the acceleration (or decelaration if you prefer) is rather violent. Without doing the math, I very much doubt that anything would be "popped off the top of the chute".
It could easily happen depending on where the object was. if it was inside of the parachute or inside of the deployment bag.
A rock of that size does not simply find its way into a plane, or into a skydiver's pocket. Gravel-sized rocks, sure. Something the size of your fist? No, just no.
Can easily find its way into a parachute, however. People who don't skydive think that parachutes are packed with surgical precision. Not the case at all.
If you could run this as a business operation, I wonder how much you could charge people for "space jumps"?
I am a licensed skydiver, and I can tell you that the way "normal" jumps are priced is there is a boarding fee generally $10-13 USD and then you pay $1 per thousand feet of altitude. This is whether you get out at 3,000 feet or 13,000 feet. But this is out of an aircraft without needing supplemental oxygen or equipment.
Specialized jumps cost more:
Hot air balloon jumps are usually around $45 and you get out anywhere between 4-6k feet.
Anything above 15,000 feet requires supplemental oxygen, so these jumps can be more expensive.
A civilian HALO jump from 30,000 feet costs around $375.
However none of that applies in this case because of all the specialized equipment for the stratos mission.
For example, the bottom of the capsule is one-use-only. Upon landing, the capsule's bottom absorbs the force of impact and "crumples", so every flight requires a replacement. There is a pressure suit which needs to fit the jumper. There is a custom parachute rig made by Velocity.
Also, the time to altitude takes a very long time, and the winds need to be just right. So it is not uncommon for them to wait days or weeks to have a window to try. They also have a large ground team. So this whole production would need to spin up for each "jumper" meaning at best you could do one or two jumpers every few weeks, at worst, one every month or two.
Not to mention each jumper would need to have a base line skydiving skill set that exceeds what most sport jumpers possess. Figure you would need to have several thousands normal skydives, including HALO jumps, before you could even begin to train for a stratos jump. Training for stratos jump would include many jumps wearing the space suit and custom velocity rig, which is not a standard rig so it has different deployment and emergency procedures. This training would need to include wind tunnel time to work on falling in a stable belly to earth orientation. It would also need to include jumps from an aircraft.
As a business operation you would likely need to charge hundreds of thousands of dollars per jumper, if not millions, and only allow "customers" who meet the qualifications.
So really, you'd have to invest several years in skydiving and have a scrooge mcduck money pond waiting for you at the end of it.
OR, you use the red bull money from all the idiots who drink red bull and you have an awesome adventure on their dime
"Take that, you hostile sons-of-bitches!" -- James Coburn, in the finale of _The_President's_Analyst_