Note: the `expect_ttx` test is passing, but the `check_ttx_dump` which ensures the TTX dump is the same after saving and reloading the font, is currently failing, as the "ValueRecordSize" count is None
```
--- /Users/cosimolupo/Documents/Github/fonttools/Tests/varLib/data/test_results/Build.ttx
+++ /var/folders/7k/fl5q53lj51g0d8hxdkrx9_z80000gn/T/tmpoBCAua/tmp1.ttx
@@ -174,8 +174,7 @@
<MVAR>
<Version value="0x00010000"/>
<Reserved value="0"/>
- <ValueRecordSize value="8"/>
- <!-- ValueRecordCount=2 -->
+ <ValueRecordSize value="None"/>
<VarStore Format="1">
<Format value="1"/>
<VarRegionList>
```