FYI: VTE 0.60 is set to deprecate the the get/set_allow_bold() methods. At some point in the future, the functionality might get removed as well (that is, the terminal will always respect if an application asks for bold text, and pick a bold font). You might consider removing this feature from your app.
Thanks for the heads up, Egmont! I'm going to keep the setting for now since I'm sure some users wouldn't be happy about removing it.