Pre-populating respondent data from checkbox matrices?

We have a survey that is repeated every few years, with unique identifiers uploaded for potential respondents.
Many items are checkbox matrices (multiple select-all-that-applies in a matrix format).
We want to either connect the surveys so the previous responses for people who completed it last time are automatically populated in many of these checkbox matrices, or somehow upload large amounts of data with our contacts/sample and use logic to pre-fill checkboxes throughout.
Qualtrics confirmed thus isn't possible out of the box but *may* be possible with custom scripting. At this point, we are trying to discover if it is indeed possible at all with custom scripting before we try to go down the path of learning how or finding an expert to work with us to do it.
Any insight?