Hi @jon,
I think that you have only 2 options here.
- Include ruleJS with Handsontable v0.14.1 (recommended by RuleJS)
- Include ruleJS with the latest Handsontable and if everything would work as expected then use this configuration (experimental)
Problem is that Handsontable-RuleJS is no longer maintained. In Q4 we plan to rewrite formula support from scratch and support it with the newest version of Handsontable.