Please test the new commit in ccr.
I immediately see the bug.
Cell C1 - SUM($A$1:A1), after saving it became SUM($A$1)
In the XML file (4.xlsx) the entry for this cell is as follows:
<c r="C1"><f>SUM($A$1:A1)</f><v>1</v></c>
This bug has no problems in working correctly, but this bug would be better fixed. It can ruin an existing Excel file and the ability to correctly copy cells will disappear.
I'll keep testing. I'll prepare my code for larger calculations soon.
Thank you very much for fixing the bugs!!!