Post still a work in progress

Create a new Gmail account.

1. Go to voice.google.com while logged into new Gmail account

2. Accept T&C of Google Voice on new Gmail account

3. GV will then try to get you to pick a phone number... DO NOT DO THIS STEP. Just logout of the new Gmail account.

4. Log into the Google Suite Legacy user account that has the GV number you want to transfer. Go to https://www.google.com/voice#phones

5. Click Transfer, a box will pop up. At the bottom it will say "Select a destination account to continue" and give you the option to "Sign-in to another account." Click that and sign into the new Gmail account you created in Step 1.

6. Once you sign in, it should be highlighted for you to choose.

7. Choose it, and complete. The transfer is instantaneous.
   Repeat for each GV number you need to transfer.

However... I would caution doing these steps too quickly or doing too many too quickly. On the first I did, I transferred it to a Gmail account I already had. On the 2nd, I created the new account one day, then waited a day before doing the transfer.

If these steps helped you, head over to RelevantActuator21 on Reddit and give them some Karma, they are the OP and deserve the credit!