It is the plates inside the battery that often get taller but the case stays the same. In other words a 215Ah - 225Ah GC2 has slightly shorter plates than does a 240Ah GC2 but they both share the same case. This can mean less room for healing before the plates can uncover. On-board installed cell orientation, to minimize plates uncovering, is still critical with any flooded battery and is an ABYC requirement with regard to flooded batteries. Some battery makers just try to stuff too many Ah's into a small case and it is not always optimal on a sailboat..That seems contrary to the geometry of the system. If the batteries were wider, the heal angle would have a more pronounced effect. However, as they are taller rather than wider, the heal angle is irrelevant. The only exception might be in an absurd case where the batteries were many feet taller.