A plastic champagne cork works well to quickly change a tarp pole connection on a tarp or rainfly. I like to use them when experimenting with various combos of pole and fabric.
The champagne cork can be temporarily held in place with a rubber band.
Here are a couple of photos to illustrate.
There are two champagne corks with poles inside them in this photo.
Here's a close-up of one of the corks showing the rubber bands holding it in place and a guy line pulling on it.