Just to clarify, mining hacks currently aim at the center of each side of a block, not the center of the block itself. See net/wurstclient/util/BlockBreaker.java for how that works.
As of v7.46, the various Nukers and VeinMiner also calculate their range using that center-of-side point, but in v7.45 the range calculation was a different algorithm which could produce slightly different results on some blocks. This might explain what happened here planetnoodle.
Cyclopropinon From the game's perspective the 8 corners don't really exist, you're always mining on one of the 6 sides of a block. But yes, getting BlockBreaker to try different points on each side that are closer to the corners would be a nice improvement, especially now that the groundwork is in place for most mining hacks to actually use BlockBreaker consistently for both mining and range checks.