Overview
I had an opportunity to convert Word files to TEI/XML files. Upon investigation, in addition to official TEI tools such as TEIGarage Conversion, I found a conversion example in TEI Publisher:
https://teipublisher.com/exist/apps/tei-publisher/test/test.docx.xml
The above example appeared to convert Word style information into TEI tags, so I tried this approach. For this project, I used the python-docx library with the goal of using it independently of TEI Publisher.
Word File
I created a prototype Word file like the one below. All styles are provisional, but I created styles such as “tei:persName” and “tei:warichu” and changed their visual styling such as color. The mechanism works by applying styles to perform simple structuring.

Conversion to TEI/XML
I created a script that takes the above Word file as input and converts it to TEI/XML, primarily based on style information. I plan to share it via pip or similar in the future.
An example of the converted TEI/XML is below. There is still much room for improvement, but I was able to convert it into a valid TEI/XML file.
<lb/>
<seg>
ワードの入力サンプル
</seg>
<lb/>
<lb/>
<seg type="dateline">
日付の行にスタイル「dateLine」を使用してください。先頭に2文字の空白が入ります。
</seg>
<lb/>
<seg type="personline">
名前の行にスタイル「personLine」を使用してください。末尾に2文字の空白が入ります。
</seg>
<lb/>
<seg>
<ruby>
<rb>
中村
</rb>
<rt>
なかむら
</rt>
<rt place="left">
さとる
</rt>
</ruby>
の形で両側ルビを記述します。緑色が左ルビです。
</seg>
<lb/>
<lb/>
<seg>
<seg type="red">
朱書
</seg> はスタイル「
<seg type="red">
red
</seg> 」を使用してください。
</seg>
<lb/>
<lb/>
<seg>
文字のサイズについては検討中です。
</seg>
<lb/>
<lb/>
<seg>
<persName>
中村覚
</persName> のような人名には、スタイル「
<persName>
persName
</persName> 」を使用してください。
</seg>
<lb/>
<lb/>
<seg>
割注は
<note type="割書">
あああああ
<milestone unit="wbr"/>
いいい
</note>
のように入力してください。正しく改行されるまで、全角スペースを入力してください。
<note type="割書">
こんな
<milestone unit="wbr"/>
スタイル
</note>
もあります。「こんな」の後に全角スペースを入れています。
</seg>
<lb/>
<lb/>
<seg type="dateline">
二〇二三年一月十七日
</seg>
<lb/>
<seg type="personline">
作成:中村覚
</seg>
<lb/>
Below is an example displayed in a TEI/XML viewer I am developing separately. Styles such as <rt place="left"> and red text have not yet been applied, but person names and interlinear notes have been successfully reproduced.

Summary
While complex structures may be difficult, I believe that being able to convert text created in Word to TEI/XML in a reasonably intended form could help lower the barrier to adopting TEI/XML. I plan to continue experimenting with this approach.