These two cards are an interesting way to keep the Level 3 Composures in play -- particularly Moxie (3) for Rogues and Plucky (3) for Survivors (Carolyn can also take these and Combat Training, if that's the route you're going). The interesting thing about the Level 3 Composures over their older Level 1 counterparts is that they soak BOTH health and sanity, and in the case of the aforementioned cards, if you want to keep them in play you'll need to soak the lower numbered soak somewhere else. So, for Plucky, you'll need a reliable damage soak, and for Survivors this is another option to Jessica Hyde (although if you're a Survivor who wants to fail, take the other version instead).

For Moxie, you need a reliable sanity soak. Hopefully with that card in play you can spend some money to not TOTALLY fail on a Rotting Remains. You can put one or two points of horror on this card and then heal it back when you inevitably fail some other test. Conversely, this card is perfect for Sefina Rousseau paired with Moxie, as she regularly has other horror soak due to Mystic access, and the damage that she puts here instead is easily healed with Rogue succeed-by-two shenanigans.

The two versions of the Precious Memento are quite a reliable soak components on their own, though I didn't pay them much attention until now. I'm currently going through my first run of Edge of the Earth, playing Daniela Reyes, and as I wanted as much soak as possible, I only realized now that these are not unique (there's no symbol on the card). Plus, the limit restriction only applies to the particular type of memento you're playing : From a future life or From a former life. This means you could potentially get the two versions of the memento in play at the same time, by just getting another accessory slot from whatever source you could afford (hence the very basic yet very powerful Relic hunter.

This is a 11xp investment, but early on in a campaign it can make a big difference if you manage to get that many xp at the end of scenario 1 or 2. Not everyone will want to get them both, often you'd prefer the campus boy or his mirror sister that come cheaper and tend to find more uses in general cases, but in a niche deck that want to take damage to do-whatever-you-wanna-do-that-for, it' a powerful investment, arguably an infinite damage/horror soak that lets you have some other allies or hand slots to close the case.

10/10 would recommend.