To flatten out the severe pucker, you need some stay tacks, an awl and a hammer.............. a couple drops of precicely place water and some heat will help. (I had latexed the edges of the miter the day before to keep it from raveling.) Stay tack the carpet into position. Add a couple of drops of water to the corner of the surging to soften it, then drive the awl into the table with the hammer to start the stretching process. I added the heat from the hair dryer later in this process and it helped. I think the photos are self descriptive. Pull on the awl slowly and allow the carpet to stretch............. add some heat, the repeat. In the last image with the awl in place, look at the distortion......... don't let it stay this way too long. Just keep working the material slow and steady until when released, it relaxes into the proper shape and stays in that position. Kinda fun to try something different. Anyone else do a surged edge this way to avoid a muter cut?

Oh My!! Did I hear hairdryer? Looks good lo. I usually do the complete miter and hand serge the corner with thread form scrap. I also save serging from rugs I have worked on before just in case I need some later. Daris

I thought about trying that on the big rug job I did a few months back but I was trying to keep as much of the border going the same direction as the carpet (I cut the borders off of a runner so I had border material going 2 directions), plus you are going to end up with 1 corner that is going to look different. If I was only doing 3 sides of something, like a landing I might try it.