Thanks for your interest. Automatically calibrating specific headlines for Facebook, Twitter and Google is a feature that is available in the pro version.
Fitting the advanced model which includes the necessary properties of social sites is a substantially more computationally intensive process — we compute an optimal headline for virality (sharing and resharing with clicks in from the social service) per platform and provide a set of tools for both your own sharing of it (as the administrator) and your visitors sharing. It is all pretty cool.
If you would like, enter your email address here: https://toolkit.iterative.ca/headlines/buy and I will keep you informed on availability of the pro version. There is no obligation to purchase, ever. ??
Automatically reposting is not currently available (as I do not think most users will want that) but we do reset the Facebook cached headline for new shares to continue the testing. Additionally, we could discuss a custom solution to reposting depending on your needs. Email me at [email protected] to discuss that further if you are interested.
Joe.
p.s., I just re-read your second paragraph. Swapping to the baseline suggests that you are trying to override the title tag — this is probably an interaction with a different plugin on your installation that is changing the <title> tag but not utilizing the WordPress title functionality. If you can send me a link to your website via email (or here) I can take a look and see if there’s a plugin interaction I can help you with (and fix for all users!).