My daughter got a Yoto for a gift last year, but unfortunately there was a recall related to prospective battery overheating. They offered a battery replacement kit (which also included the NFC Reader and so was likely a good portion of the overall hardware). While it took a little while to arrive, the process was very straightforward with everything necessary included in the kit and good documentation.
Towards the end of last year I read through the second edition of Data Management at Scale(1) (and just retrofitted a reference to it which made me think of it. Its certainly worth a read - it provides a good high level overview of many aspects of data management. It likely could have been a bit more succinct by focusing more on the core of data management, but all of the information was framed within the larger concept (unlike other books in the space (like the Data Engineering one) which seem to spend far too long on general technology topics. All of these are governed by my bias where I look for books to provide insights for a particular area and fill a specific role wihin a larger corpus rather than broad guidance which overlaps with other topics.
Likely the most important aspect to call out is that it is largely high-level; it's useful for me as an architect to be able to explain and reconcile data management strategy decisions across an organization and in relation to other systems - but it's very light on guidance on how to implement such systems. It does a good job of trying to pin down many of the concepts that are currently floating around in the data management space and some patterns for how they may fit together and where they may be appropriate.
As an extension of starting to dig more deeply into nix, I've decided to swap my home "server" over to NixOS. I don't yet actively use the server for much, but it is a system that I ostensibly leave on and provide a bunch of storage. Currently it's running Gentoo since that's been my default distribution for a long time now (and will remain what I run on my laptop/workstation at least for the time being). The first step is the typical one whenever I want to do something like this which is to track down some USB bootable media.