I would love to get a UNIQUE function to work on 1) any list of things and 2) answers in multiselects across repeats.
For example #1:
Granted, this is pretty niche, but I'm sure there are other applications: Solved: Cascading Multi-selects: Only showing unique choic... - Esri Community (Also it has to do with multiselects as well, but again, I'm sure there are other applications).
For example #2:
I was working on a form that needed to get a cumulative review of many questions in a repeat. For Single-choices, it was a pretty simple ranking of the answers using nested ifs.
Name | Calculation |
finculvcal | join("; ", ${culverts}) |
finculv | if(count(${culverts})>0, if(contains(${finculvcal}, 'Major Issues (significant blockages or failure)'), 'Major Issues (significant blockages or failure)', if(contains(${finculvcal}, 'Moderate Issues (frequent blockages or partial failure)'), 'Moderate Issues (frequent blockages or partial failure)', if(contains(${finculvcal}, 'Minor Issues (some blockages, but manageable)'), 'Minor Issues (some blockages, but manageable)', if(contains(${finculvcal}, 'Clear (no blockages, functioning properly)'), 'Clear (no blockages, functioning properly)', if(contains(${finculvcal}, 'N/A'), 'N/A', ""))))), "") |
For multiselects, it's a lot more complicated:

NAME | Calculation |
calc | join("; ", ${culverts}) |
finculv0 | if(not(contains(${calc}, "Clear")) and not(contains(${calc}, "Minor")) and not(contains(${calc}, "Moderate")) and not(contains(${calc}, "Major")) and contains(${calc}, "N/A"), "N/A", "") |
finculv1 | if(contains(${calc}, "Clear"), "Clear,", "") |
finculv2 | if(contains(${calc}, "Minor"), "Minor,", "") |
finculv3 | if(contains(${calc}, "Moderate"), "Moderate,", "") |
finculv4 | if(contains(${calc}, "Major"), "Major,", "") |
finculv | concat(${finculv0},${finculv1}, ${finculv2}, ${finculv3}, ${finculv4}) |
(For the record, all of these except for finculv were calculations bound to Null; they do not actually appear to the user).
It would have been SO MUCH easier to just unique(${culvert}).
Please add in a UNIQUE function.