To extract the VIs out of LEIF section (produced by Fast File Format option) you may try my instruction above. Depending on the number of the VIs in your executable and their hierarchy it may be not that easy, but it's definitely doable at least.
I confirm that in LabVIEW 2020 (both 32- and 64-bit) on Windows. 32-bit LabVIEW dies silently in case of the error, whereas 64-bit LabVIEW shows the following report.