MD Plus Controller Alias Resolution

From Books Online, it is stated that for a MD Plus controller, the maximum recommended limit for “Alias resolution information for units in a single controller” is not more than 50. Some clarifications needed:-

1.    Does this limit only apply when a phase runs? The unit module that runs the phase currently has about 90 assigned aliases (i.e. not ignored), but only about 35 of them are required/used in the phase.

2.    When a phase executes in the controller, alias resolution in the controller is for all 90 aliases assigned to the unit or only those as required by the phase?