We are using Quform 2.14.2 and Excel 2016 (16.0.5188.1000).
It turns out I hadn’t tested the CSV export with the fix (# version). With the # fix, the Excel export still has the rounding issue, but the CSV is actually correct!
With no fix and with the @ fix, both CSV and Excel 2007 are incorrect (CSV has the number in scientific notation; Excel does as well, and when you click the cell, the function bar shows the number in regular format, but rounded).
Interestingly – exporting as Excel 2005 is correct, even with no fix in place.
I’m still interested in a fix for Excel 2007 format if possible, but I’m glad to have some export options that preserve the number!
I appreciate the help!