In "archive" mode, gpgme's gpg engine calls gpgtar (instead of gpg) with the following general options most of which probably need to be supported natively by gpgtar instead of being forwarded via --gpg-args to gpg:
--homedir --no-tty --charset --display --ttyname --ttytype --logger-fd
I'm not sure about
which are also set by the engine's gpg_new. Those options could probably be set later in build_argv when we already know that we want to call gpgtar instead of gpg.