I absolutely love the new lime. I have been living with 2.5 for years now and am finally re-writing all of our custom junk for the newest version. I have ran into an issue on php 7.2 for question theme options. readonly_when_active false is a string so its being validated as true and the advanced option inputs are loading disabled once the survey is live. It was an easy fix but made me think that since themes at template or question level all use the xml configs, maybe a schema for setting proper types might be a good idea.

Empty string is false secure.php.net/manual/en/language.types.boolean.php

Then set default value to "" send false, no ?

But more : default is set (or must be set) here : github.com/LimeSurvey/LimeSurvey/blob/36...onAttribute.php#L305

Then : not send it in your xml and you have your false. Send it to 1 or " " return true.

PS : but you're right , a clean schema is something to be done