I'm trying to evaluate the degree to which Fate of Cthulhu is worth my time, money, and either waiting time or hassle related to buying specifically the PDF (I have no need for the dead tree version which is currently bundled with it). This evaluation hinges on two main factors: the Condensed rulebook (which seems worth it), and the handling of time travel (about which I'd like to find out more).
I have seen short reviews indicate that the book offers good ways to handle the usual concerns of time travel such as paradoxes. However, what that actually means and how useful that is to me depends on an unstated assumption/context, which I'd like to know about:
Which model of time travel has been chosen when writing the setting and ruleset, and which of the common switches and toggles related to that model are in what states? Does it even have a coherent model of time travel? (After all, some franchises resort to 'solving' paradoxes by way of a timey-wimey ball.)
If the heart of the question looks ambiguous, here's a bit of a clarification: when I talk of the models of time travel, I mean those such as in this simplified list. Note that the list is just a starting point; it doesn't go deep into exploring switches and toggles, e.g. how the Sensitive History model can be made more consistent and playable by use of Achron-style meta-time and change-propagation principles, or how adjusting the 'speed' of time waves can produce different scenarios and overall feel of a story/campaign/game.