There were a couple of problems, on both the front and back ends, that 

prevented text types from being set and handled correctly for custom 

fields. 
The primary issue was that the <filename>_text_type metadata was not 

being stored into the extra_data dictionary on the review request. 

Investigation revealed that this item was being set correctly on the 

review request draft, but was not being propagated upon publishing. The 

root cause of this lies in ReviewRequestDraft.copy_fields_to_request 

where changed fields are identified and their value's are copied 

from draft to request. Nominally, fields only contain values and this 

copying process is fine, but fields derived from BaseTextAreaField 

have both a value and an associated text type metadata element. This 

issue is resolved by adding a new propagate_data method to the 

BaseReviewRequestField base class, which is now called in 

copy_fields_to_request. This method assumes the responsibility for 

copying value's from draft to review request. In BaseTextAreaField the 

method is extended to also copy text type metadata. 
Additionally there were a couple of problems on the front end which 

prevented the Enable Markdown checkbox from always being set correctly 

for custom fields. The getDraftField method in ReviewRequestEditor 

has logic for handing the useExtraData case and was always getting 

options.fieldID from extraData, while ignoring the fieldName 

parameter passed into the function. This had the effect of always 

returning the value associated with a custom field, regardless of what 

data element the caller may have actually been asking for. Specifically, 

this prevented the retrieval of the rich text attribute associated with 

the field. Additionally in ReviewRequestEditorView.render the name of 

the rich text attribute was being incorrectly set to 

<fieldname>_rich_text rather than <fieldname>RichText. This was 

problematic because the later naming syntax is assumed in other places 

for accessing the rich text attribute. Finally, in 

ReviewRequestEditorView.registerField the naming convention of the 

text type field for the special case field name of 'text' was 

incorrectly using text_text_type rather than text_type. All of these 

problems have been resolved.

Added Python unit tests which failed before the back end fixes. 

Successfully executed all unit tests. 
Added Javascript unit tests which failed before the front end fixes. 

Successfully executed all unit tests. 
Lots of manual testing with Note to Reviewers extension. Observed 

that beanbag_notefield_notes_text_type key-value pair is now correctly 

serialized to the database in extra_data, markdown text is now 

correctly rendered, and markdown checkbox state is sensible.