Typescript errors occur when taking variables in modifiers that are also used as compound modifiers

[JaredMaione]

🐛 Bug Report

If we have a stencil like the following:
const stencil = createStencil({
     vars: {
        var1: ''
    },
    base: ({var1}) => ({
        // base styles here including usage of var1
    }),
    modifiers: {
        modifier1: {
            true: ({var1}) => ({
                 // any other applicable constant options for the modifier would be present here
                backgroundColor: var1
            })
        },
        modifier2: {
            true: {
                // modifier2 styles here
            }
        }
    },
    compound: [
        {
            modifiers: {modifier1: 'true', modifier2: 'true'},
                styles: {
                    // compound modifier styles
                }
        }
    ]
});

We get type errors in the compound section: TS2322: Type string is not assignable to type boolean | undefined. The expected type comes from property modifier1 which is declared here on type...

Additionally, when using the stencil, we see TS2322: Type boolean is not assignable to type string.

It is functionally working fine, it's just a typing issue.

To Reproduce

An example stencil can be set up like the above

Expected Behavior

There should not be type errors in this scenario

Actual Results

TS gives errors in the stencil definition as well as when trying to use it

Browser (if applicable)

N/A