Gallery Fiter/Query Timing and Performance

[Phineas]

I have a Toggle control. The Toggle control allows the user the ability to choose between 'four' (4) 'Category' types.

I have four Galleries. Each Gallery represents data associated with the 'Category' type chosen in the Toggle control.

I have each Gallery's Visible and Items property tied to the choice made in the Toggle control.

I am using the formula below in the Items of each Gallery.

As I understand the process each Gallery is going to auto-populate data based on the 'Category' identified in each formula at 'App Start', regardless of the choice made in the Toggle control, which is blank at start.

Question 1: Does it adversely impact load-time, performance, or delegation that each Gallery auto-populates at 'App Start'?

Question 2: If the answer to the above is "yes", is there a way to edit the below formula to ONLY retrieve the data for each Gallery when the Toggle control has been changed to the associated 'Category'?

Desired Outcome: The following should not begin until the User changes the Toggle (the below formula is from the 'Status'

                              Gallery).

Gallery Items Property: 

If(!IsBlank(ReviewScreenEventDateRangeCheckbox),
Filter(
'Test List',
DateOfEvent>DateAdd(ReviewScreenEventStartDatePicker.SelectedDate,-1,Days)
&&
DateOfEvent<DateAdd(ReviewScreenEventEndDatePicker.SelectedDate,1,Days) &&
Len(ReviewScreenSearchComboBox.Selected.Value) = 0 ||
StartsWith(
Status,
ReviewScreenSearchComboBox.Selected.Value)
),

Sort(
Filter(
'Test List',
Len(ReviewScreenSearchComboBox.Selected.Value) = 0 ||
StartsWith(
Status,
ReviewScreenSearchComboBox.Selected.Value)
),
varSortGallery
))