Wow, your poor phone number has been through the carrier rodeo. Good luck.
Just a tip, if you do decide to go through this route (I realize you've done this once before):
The single greatest cause of GV number porting failures is user error, in submitting incorrect validation information to the carriers. This causes endless problems, requiring manual intervention to clean out and re-start.
So: if you port your number out to GoPhone, then a) be sure to wait a few days and let the dust settle before taking any action, then b) contact GoPhone customer support and specifically ask them something like "It turns out that I actually need to port my number out of GoPhone to another carrier. Would you please give me the account number I need to give that carrier, to authenticate my GoPhone account for porting?" This account number is NOT displayed to you on your GoPhone portal page. The PIN is the one you use to view your account details on the GoPhone portal, not necessarily the same as your voicemail PIN. Similar steps apply if you use T-Mobile as your patsy er, intermediate porting point. Do NOT port it into some hybrid Mickey Mouse carrier like Republic or RingPlus or FreedomPOP.