That's right, and it's also available by right-clicking on the text ("T-t") just above the threshold slider. Occasionally, these will have slightly different behavior depending on the operating system. And in case, this is a repetitive situtation, consider scripting this with a plugout script with this plugout_drive option:
SET_THRESHNEW [c] val [flags]
Sets the threshold slider for controller index 'c' (default='A') to the
numerical value 'val', which must be in the range [0..9999]. If the
optional 'flags' string contains the character '*', then the slider decimal
offset (i.e., the '**' setting) will be changed to match the size of 'val'.
If 'flags' contains the character 'p', then 'val will be interepreted as
a p-value (and so must be between 0.0 and 1.0). Examples:
SET_THRESHNEW A 9.2731
SET_THRESHNEW B 0.3971 *p
