How many instances of the plugin is Liquid Mix capable of handling?

The number of Liquid Mix plugins which can run at one time will depend upon the sampling rate of the recording session. The number of allowed plugins for each of the possible sampling rates is shown below:

@44.1kHz - 48kHz: up to 32 mono / 16 stereo
@88.2kHz - 96kHz: up to 8 mono / 4 stereo
@176.4kHz - 192kHz: up to 2 mono / 1 stereo