Is this ugly-looking graft union going to be an issue for my apple tree in the future? 🌱 Enough to replace it now? Or where else could I ask this Q for an educated option as I have no idea but keep wondering if I need to cut losses or am I overthinking the damage 🤔

Ugh, I really don't like that heavily split bark. It's not just a fungus risk, it stands the risk of basically peeling off what phloem connection exists if it spreads, wherein, game over.

I had one that looked somewhat similar, the apple graft died and the root stock sprouted.