A New Year's Rube Goldberg approach to Google Voice Transcription of messages to yourself:
1. Setup a new Google Voice Account.
a. Do not link this new GV# to your OBi or configure it on the OBi.
b. Use an external (non-gmail) email address as the user name on the new GV#. You do not need an associated gmail account.
c. Under the GV Settings Calls tab Enable "Do Not Disturb" with no end time.
This will route incoming calls directly to leave a voicemail.
d. Under the GV Settings Voicemail & Text tab Voicemail Notifications Alert me when I have new voicemails
check and set the "Email the message to: your-external-non-gmail-address" and check the Voicemail Transcripts Transcribe Voicemails box.
2. Configure a forwarding rule (filter) at your external email (non-gmail) provider used in 1.d for messages with
"New voicemail from (xxx) xxx-xxxx" in the subject line (replacing the x's with the home phone you'll be dialing from)
and setting the to: address on the forwarding rule to your existing gmail account.
Or you might get away with forwarding all messages from:
voice-noreply@google.com instead of the specific subject line depending
on your situation.
3. On your OBi setup a speed dial for the new GV# setup in #1. Dial this speed dial to leave messages to yourself.
Advantages to this approach: You don't have to wait 25 seconds for the voice message prompt to kick in and doesn't require tying
up a second SPx with a second GV# unless you really want or need another GV# on a second SPx.