I feel dumb now. There is no configuration of the SpoofCallerID flag...it's a flag, so it's either on or off. When you turn it on, OBI spoofs the inbound CID when you transfer a call.
Confirmation from this very forum:
http://www.obitalk.com/forum/index.php?topic=530.msg3269#msg3269Voip.ms appears to allow this: I was able to warm transfer the call from my cell phone to Jolly Roger and connect.
Blind transfer still is not working but I will need a third phone number to test that (no luck transferring myself back to the inbound number). I'll experiment later tonight, or sooner if a telemarketer calls in the meantime.
Edit: Blind transfer (*98) doesn't work. It just calls the calling inbound. If I was calling a 3rd-party human, it would work perfectly, but calling back the inbound doesn't.
Edit 2: Caller ID spoofing of the inbound number is not working. I have a workaround...I will just blacklist my own number in Jolly Roger. Ugly, but it will work.
Edit 3: It works. Removing the CID from the
VOIP.ms config sends the sub-account ID as CID; in my case 123xx456_555MYNUMBER. Jolly Roger truncates this at 123xx456; I have blacklisted this CID.