Here is what I would do.
In your OnApp Start, create 2 collections, 1 from the Person information list and one from the task list.
Have 2 galleries.
In the first gallery Items property put your Person Information Collection. In the second gallery put your tasks collection. I don't know if there are different tasks for each user, so you might have to filter the tasks to only show the ones that apply to the specific user.
In Gallery 1, set the OnSelect property of your icon to Set(varRecord, ThisItem). This is going to give us some information to use when the tasks are saved.
Set the Second Gallery to the Title layout. Add a checkbox input and delete the other label. Select the Checkbox control and set it's items to the column that contains the task name.
This would look something like this:
In the image below #1 shows what it would look like when applying the formula shown above to the Text property of the checkbox. You can delete the 2nd gallery arrow icon shown at number #2,
Gallery 2 Example
If necessary in your Gallery 2 Items filter so only tasks that apply to the selected person show up.
In your gallery 2 in the OnCheck property of the checkbox set a formula like this:
Collect(CollectionName, ThisItem)
In the OnUncheck Property set this:
Remove(CollectionName, ThisItem)
When you are finished, in your save button/icon in the OnSelect, you will add this information to the person list.
I don't know what type of column you have that will hold the tasks, but if you are going to use a single line of text field you would do something like this:
UpdateIf(
PersonListDataSource, varRecordID = ID,
{
TaskColumn: Match(Concat(CollectionName, ColumnName & ", "),"^(?<trim>.*), $").trim
}
)
