Years ago I had to drill holes in the back of my pontoon logs to drain out water. I used these as the plugs to keep the tubes watertight for a several outings until the dealer got the boat in, fixed the leaks and welded 3/8 NPT aluminum half couplings in the drilled out holes to permanently close of the drains, while allowing for NPT plugs to be removed if any leaks showed up in the future. I cleared this drain hole drill and drain location with the dealer before I did it. I wanted to use the boat and he couldn't fix it for a few weeks so this was the temp fix.
To be clear the plugs were in the tube walls for 12 or 16 hours at a time while the boat was in the water for a trip. They were taken out and the boat was trailered between trips. They were in the rounded end cap of the tube, which might have been .060 thick, not much more. I was concerned about the same cutting you mentioned, but never saw any sign of it. I probably used it this way for a half dozen trips.