Yeah, did this already. They told me to renew and asked why I wanted to transfer. ($11.99 renewal fee when there's better options available for $8-9 is obvious)
Dynadot have never refused to unlock the expired domain or refused for me to obtain the auth code. I've had 100% success (of admittedly very few requests). Why would I want to transfer away from Dynadot? They are my preferred Registrar.