The editing of the rate settings is limited by Connect IQ.
It is not possible to switch the contextualisation of the rate settings when switching between the two modes of the app (timed intervals and beats per minute).
The range for the "rate mode" is 1-599 seconds.
The functional range for the "Beats per Minute" mode is 1-60. If a setting of greater than 60 is entered, the datafield defaults this to 60.
There is an open issue on this in case a neater alternative solution can be found.