@Josh Check out GitHub - Sjlver/yxf: Convert from XLSForm to YAML and back version 0.2.0
It generates Markdown when the --markdown parameter is specified.
The format is almost the same as yours, except that yxf uses ## survey for the table names instead of %% survey. It understands the %% syntax when reading files, but does not support writing it. The reason is that using headings seemed more natural to me.
Example conversion:

## survey
Converted by yxf, from basics-converted.xlsx. Edit the Markdown file instead of the Excel file.
Hello, this is *an emphasized* <u>comment</u>.
| type | name | label |
| ---------------- | ---- | ------------------------------------------------------------- |
| text | name | What is \| your name? Please tell me, I'm **really curious**! |
| integer | age | How old are you? |
| select_one foods | food | What is your favourite meal? |
Feedback and bug reports are welcome!
