Randomly selecting more than one person

Hi all,
I am using XLForm. Attached is my code for randomly selecting a household member above the age of 18 to continue taking the second part of a survey after finishing the first part. ODK automatically uses the names inputted in the first "repeat" group picks from those. This only works in ODK Collect 10.2, not Enketo (don't know about other platforms).

My question: my survey will take approximately 1 hour to administer. The head of the household answers the first part of the survey, but anyone above the age of 18 is eligible to answer the second part of the survey. Since I input the names of the household members in the beginning, and do the randomization at the end, I assume that some people who are present in the beginning of the survey (or never were present), won't be present to do the second part of the survey. If ODK selects a person who isn't available, I want the enumerator to select "not available", at which time ODK will select another eligible person to take the second part of the survey.

How do I go about do this? I tried to cut and copy the randomization part of the form, but ODK continues to select the same person again and again. I think that the easiest way would be to remove that person that was selected, and will not continue with the survey, off of the list. Then, ODK would run the randomization again, this time with the new list (the old list, minus the ineligible person).

Any help would be greatly appreciated. Thank you!

RandomizationODK_multiplepeople.xlsx (31.0 KB)