Something to look for is whether the Image Cast Central (ICC) system stores this JSON data as plaintext or in an encrypted form.
If this json is stored as plain text, then modifying election data before it is turned into the custody of the county is trivial.
Archiv: JSON (JavaScript Object Notation)
NIST Special Publication 1500-100: Election Results Common Data Format Specification
(December 2019)
1.1 Why this specification is needed The purpose of this specification is to provide a comprehensive, flexible, and interoperable pre-election setup and post-election results reporting XML and JSON format for manufacturers to integrate into their voting equipment and for election offices, the media, and other groups to use in their own software. Some advantages of using this specification are that:
• election results can be reported directly from election offices in this format regardless of voting system manufacturer, thus enabling interoperability;
• the need for custom software and custom reporting formats is greatly reduced;
• jurisdictions that use multiple versions of EMSs and tabulators can more easily combine and transfer information between systems
It seems election votes are tallied then stored as a DOUBLE in JSON. „can include a factional [sic] component in special cases“
If it is proven that Dominion uses this standard in their machines, then that is proof that votes are stored ultimately as double length floating point numbers.