Keep Google Voice From Disabling SMS on Feature Phones

This is a problem that's been driving me crazy for almost a year now, and thankfully it turns out that it's all my fault.

I have an Android "phone" that lives in airplane mode, and a feature phone that I occasionally use to receive calls and texts. Most of my outgoing calls happen either from my Android (via a an app called "GVoice Callback" over wifi to my feature phone) or from my computer (From the Google Voice webpage to the Gmail webpage). Most of my outgoing sms messages are sent from the Google Voice webpage, though many are also sent from my Android's Google Voice app. Very rarely do I send a text from my feature phone, but it happens.

For quite a while now, I would open up https://www.google.com/voice#phones and choose my feature phone, select "Receive text messages on this phone" and for a time it would send any texts received to my feature phone, on the off chance I was away from Wifi and needed to be contacted. After doing that, I would stop getting texts automatically sent to my Google Voice app on my Android. 

To make a longer story shorter: in the official Google Voice app for Android, you're required (for some reason) to set a number for the phone you're using the app on. If you--like me--don't actually have a number for your android and foolishly chose your feature phone's number, then you will have the same issue. It turns out that the phone-specific setting chosen on your Android is synced to the phone-specific settings on the Google Voice webpage. Checking the box labeled
"Receive text messages on this phone" on the webpage, sets the Android app (under Sync and notifications) to "Receive text messages ... Via the messaging app", which disables sms sync on the Google Voice app. 

To fix it, I simply told my Android app that it was my home phone's number. If you don't have a home phone (and really, why would you) then presumably any number that you don't want to receive text messages on will do the trick, be this your SIP number, an old Gizmo5 number, or really any number you can receive a voice call on once a month to verify with Google.