I've done a few...........hundred.
I once put 68 plugs in the tires on my truck in an afternoon. Got pretty good at it actually.
Also put about 25 in one hole on a boat trailer tire. We were a long way from home and on our way fishing when a piece of metal cut the tire.
No spare, so just for fun I started putting plugs in next to plugs.
Actually sort of built a piece of tire.
It got us to where we were going and back home that night.
Kept it for a spare for a couple of years, finally sold it with the boat. Always wondered if the new owner had to use it.........
Many years back, I saw a Michelin service manual for patching their tires. They had maximum hole size and location limits.
One of the things they stressed, was that the inside had to be patched, and the hole filled to prevent the steel belts from rusting and failing.
I have since seen some steel belted tires that failed when the belts rusted out inside the tire from a cut that was not repaired or just not noticed.
There used to be a great way of doing it. It was a round patch with the sticky rubber that acts as a glue when you put on the solvent on one side, and a rubber shaft coming out of the center of the patch with the same stuff on it.
You broke down the tire, buffed out the area around the hole inside, worked the solvent into the hole well, then inserted a tool through the tire.
Put the solvent on the patch and the cleaned area of the inside of the tire. Then pulled the shaft out through the tire until the patch was pulled snug against the inside.
Then you use the little roller to stitch it down and cut the shaft off flush with the outside.
That way, the hole is filled and sealed so no water can get in, and the inside is sealed with the patch so no air will get out.