Uneven spine wear and bevels are normal. No razors are perfectly ground, and the exact same width and thickness. Some are close, yours is. Do not attempt to “fix” the spine, you already have. The spine, bevel and edge are now in perfect alignment, in the same plane.
Adding tape will increase the angle and cut a new microscopically steeper bevel, depending on how many laps you do and the grit of the stone, it can cut a micro or whole new bevel. Modern synthetic stones are much more aggressive that folks think. Here is an old thread on chip removal and honing on a 12k super stone in about 200 laps, (12K Chip Removal/Bevel Setting) Re-setting a taped bevel is a fraction of removing a chip, as Glen demonstrated.
Try the Kapton tape on eBay, about $10 a roll, it is thin and tough, if you want the spine to remain where it is now.
“LE: another point I would like to clarify is that I don't have a problem with spine wear, but rather with uneven spine wear. This is why I have not used tape.”
I do not understand this comment, if you used tape you would have no, spine wear.