I like JVH's simple modified kenjig idea. I believe the future will see even more of us increasingly using diamon and/or CBN wheels which do not change diameter. Hopefully we are mostly beyond the nonsense of 253mm diameter wheels, which I believe are really ten inch, a mistake for a metric machine.
I also believe wheel wear with knives is overblown. Yes, conventional wheels do wear. However, the bevel angle of scrapers is not critical. Worst case scenario, the simple jig will get you very close. Using the black marker should cover the fine tuning.
Ken