It should be, but depends on what your function is returning. Are you able to share your code / xlsform?
Oh! I see, you'd like the list of choices filtered, not just pre-selected. I think the only way to do this is to utilize the choice_filter column. See: https://community.esri.com/t5/arcgis-survey123-blog/survey123-tricks-of-the-trade-choice-filters/ba-...
I haven't combined a JS function and a choice filter before, but this is still doable using a hidden question and a choice filter.
Here's my test. You can see that my options are limited to those items in my string list.
EDIT: I should say, set that hidden question to a null type so it's not part of the output schema.
That is a slick way to filter a list of choices that already exist. In my case, I would have to put 100's of thousands of choices into the spreadsheet to cover all the possibilities that are stored in the feature service. What I am looking to do is dynamically define the choices without having to store any predefined values in the excel choice tab.
You'll probably want an external choice list, then. I haven't worked with them much, but perhaps you could export your layer's vales from the relevant column(s) to a CSV?