Any sharp corner is a potential crack or tear waiting to happen, when the accumulated fatigue effects exceed what the material can handle.Mine split the other way. If you look at the bore it has grease grooves, they are square, not round, bad design. I wonder if the square or sharp corner is another design flaw. I think these bushings fail for a lot of people. Go with delrin.
This is one of those things I'd take a shot at just to see if I could improve it.I wouldn’t put too much thought into trying to fix these, everyone I know with one glaring exception (who doesn’t run them anymore) has gone through multiple sets. Sometimes failing as quickly as one session. For the cost and hassle, the Delrin and FPP offerings are far better and more reliable.