Actually, it worked: the grafted branch was severed from the pot, and after ten days or so, it was continuing to develop. So I removed the buddy-tape, and moved the pot to my working bench. Unfortunately, if the branch was not fully sealed to the trunk and since it was quite long, its weight caused it to fall from the trunk.
Precipitation=trouble, I should have known.
But this year, I spotted two small branches starting to grow lower down the trunk, so I decided to defoliate it except these two branches.
Only ten days later, it already had a lot of new leaves. July 13th:
But what struck me was this first branch on the smaller tree: much too straight and big. There's at least a twig that might replace it. This is a virtual I made:
I would say no - or at least not until I had tried another approach.
Looking at your 'problem' first branch, there is a small branch coming off it (point down or towards the viewer?) around one third of the way along - the first significant secondary branch. I would try making the cut just after that branch, so that the sub-branch becomes the 'leader'. That way you lose much of the straightness, but have some movement and taper.
Keep the branch you might want to remove small and try to induce taper, but keep it. After you established the new branch the tree will develop a different feeling and you can go ahead and follow that feeling. Most of the time the lowest branch should be on the lowest tree. The place both branches (new and the removable one) are approximately at the same height and might visually distort the image. Adding more movement in those can sort out that problem.
I think your virt is lovely as it is. I believe that first branch must go because it will always compete w the trunk it is on for thickness, and will make the branches of the main tree look too thin as well. It seems you should be able to put a little movement in the smaller trunk, with a clamp if necessary. It wouldn't take much. If the 'French' virt is possible it would be ok, but again, if you can make that bend, you should be able to make a bend in the trunk.
I would be very surprised if your approach graft was successful. What you are trying to do with an approach graft is align two layers of cambium that run in the same direction. The longer the area that is matched up, the more likely your graft will be to take. A graft at a right angle to the cambium layer is much less likely to take (though not impossible).
I think you would be more successful with a small thread graft since you are really just looking for a small branch at that location that you can grow out. Additionally, a thread graft will be more sturdy and less likely to fall off in the wind.
To my eye, your solution is much better than the earlier possibilities of shortening or removing that branch. Your solution even makes the straight trunk less noticeable -- because it's shorter now, I suppose.