402653184edo
402,653,184-EDO is an equal-step tuning system that allows for finer subdivisions within the standard 128-note MIDI scale based on 12-EDO, using 32-bit data.
Since 128 notes equal 2^7, this leaves 25 additional bits for further subdivision of the 12-tone equal temperament. By calculating 12 * 2^25, we arrive at a system with 402,653,184 equally spaced divisions of the octave.
It could be applied through the 7.25 pitch attribute introduced in MIDI 2.0.