Enable "Replace Data Function" if a new .sfd is available

Say I have a data function (e.g. TERR) embedded within a Spotfire file.  An updated copy of that data function becomes available as an .sfd file (maybe I sent a copy of the Spotfire dxp to a colleage, or to a different VM environment, and an improvement was made to the data function).   It would be nice to be able to update the data function in the first dxp file, with this new .sfd definition.   (Obviously if the inputs/outputs change, these must be accommodated somehow.)

This situation comes up when I maintain a "reference" dxp in an older version of Spotfire to maximize compatibility, and somebody produces a separate dxp file in a newer version of Spotfire, using the latest formatting etc.   I then make some kind of edit to the data function in one of these files. I don't want to delete either one of these dxp files, but rather I'd like to transfer the data function definition from one to the other.   And I don't want to delete the data function and have to wire it up again from scratch.