===Background
The deployment of T239676 will introduce an option for all contributors, including those included in our ongoing A/B test [1], to opt into the mobile wikitext editor, even in instances when the mobile visualeditor would have otherwise loaded by default. [2]
To ensure these contributors are appropriately accounted for in our analysis, we will need to add new tracking events that enable us to see which users assigned to the `default-visual` bucket have opted into the mobile wikitext editor by way of the new "fallback workflow" T239767 will introduce.
=== Done
- [ ] Instrumentation is added to track contributors who engage with the "mobile wikitext fallback" workflow such that we can segment them in our analysis (T221198)
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1. {T227338}
2. E.g. a contributor in the A/B test could be assigned to the `default-visual` bucket, but elect to use the mobile wikitext editor if they felt the mobile visual editor was taking too long to load.
3. {T221198}