Given this Handlebars template as input:

<span class="{{classes}}"></span>

When removeAttributeQuotes: true is set, the quotes will (presumably rightfully) be removed giving this result:

<span class={{classes}}></span>

To keep the quotes (because the variable can resolve to a value containing spaces) I added ignoreCustomFragments: [/"\{\{.*?\}\}"/], which results in double double-quotes like in the result:

<span class=""{{classes}}""></span>

Is that expected? It seems the value of removeAttributeQuotes has no effect on these quotes.