While 128 steps seems to be sufficient for most controls, it doesn't work for everything. Especially when controlling something with pitch and some filters, a clearly noticeable stepping can occur.

For this, the decades old MIDI 1.0 standard has implemented 14-Bit MIDI, which simply uses two CC values to allow values from 0-16383

Various hardware controllers like Faderfox UC4/EC4 can send 14-Bit high resolution CC values, but also apps like 4Pockets Surface Builder.

There does not seem to be any iOS-specific DAW/AUv3 hosts at the moment that supports this extremely useful MIDI standard.

BAM could be first.

The implementation would also require to increase the automation resolution which, i could be wrong, seems to be at 128 steps at the moment.