Order of operations: slot content with WebC Transforms

So imagine a webc component named reverse. The idea is to take content from the default slot and reverse it. It would be used like so:

<reverse>
This is a test.
</reverse>

And the output would simply reverse that string. I tried doing this with Liquid, like so:

<template webc:type="11ty" 11ty:type="liquid">

  {% capture content %}
  <slot><p>Im the default slot.</p></slot>
  {% endcapture %}

  <p>
  Content: {{ content }}
  </p>

  <p>
  Content reversed: {{ content | split: "" | reverse | join: "" }}
  </p>
</template>

The output was... unusual:

Content: This is a test.

Im the default slot.

Content reversed: >tols/<>p/<.tols tluafed eht mI>p<>tols<

It correctly captured the default slot, but then output the default text as if I had not passed any in. And then - oddly - despite the content variable being correct, when the split/reverse/join is called, it used the raw HTML.

You can see this here:

https://glitch.com/edit/#!/determined-honorable-porch?path=src%2F_includes%2F_components%2Freverse.webc%3A18%3A0

Reproduce the behavior in the linked Glitch example, starting with src/_includes/components/reverse.webc around line 18 and its Liquid template. Compare the captured default-slot value with the value passed through split, reverse, and join. Done means the slot is not emitted unexpectedly and the reverse operation uses the intended captured content.