It’s always best to provide details about what you’ve tried, reduced to the most concise real-world example.
If you mean Can I have two sibling elements, only one of which is shown based on a boolean toggle” then yes, like so:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta class="mktoBoolean" mktoName="Overall Theme" id="globalTheme" true_value_name="Theme A" false_value_name="Theme B" true_value="theme-a" false_value="theme-b" default="true">
<title></title>
<style>
.themable {
display: none;
}
.themable.${globalTheme} {
display: block;
}
</style>
</head>
<body>
<div class="mktoText themable theme-a" id="exampleTextA" mktoName="Text Area A">
This is an example editable text area in Theme A.
</div>
<div class="mktoText themable theme-b" id="exampleTextB" mktoName="Text Area B">
This is an example editable text area in Theme B.
</div>
</body>
</html>